ELSEVIER''''S DICTIONARY OF PSYCHOLOGICAL THEORIES phần 10 potx

In general, theories of lance refer to the systematic accounts of how observers maintain their focus of attention vigi-i.e., the selective aspects of perception that function to help an

cally in perception) See also

CARPEN-TERED-WORLD HYPOTHESIS;

SCIOUSNESS, PHENOMENON OF;

CON-STRUCTIVIST THEORY OF

PERCEP-TION; EMPIRICIST VERSUS NATIVIST

THEORIES; PERCEPTION (I GENERAL),

THEORIES OF; PERCEPTION (II

COM-PARATIVE APPRAISAL), THEORIES OF

REFERENCES

Helmholtz, H von (1856-1866) Physiological

optics Leipzig: Voss

Wundt, W (1862) Beitrage zur theorie der

sinneswahrnehmung Leipzig:

Wun-ter’sck

Freud, S (1915) The unconscious In The

standard edition of the complete

psychological works of Sigmund

Freud London: Hogarth Press

Hochberg, J (1994) Unconscious inference

In R J Corsini (Ed.), Encyclopedia

of psychology New York: Wiley

Chalmers, D (1996) The conscious mind: In

search of a fundamental theory

New York: Oxford University Press

UNCONSCIOUS

MEMORY/UNCON-SCIOUSNESS THEORY See

FORGET-TING/MEMORY, THEORIES OF; FREUD’S

THEORY OF PERSONALITY;

UNCON-SCIOUS INFERENCE, DOCTRINE OF

UNDERSTIMULATION THEORY See

PSYCHOPATHOLGY, THEORIES OF

UNDULATORY THEORY See VISION/

SIGHT, THEORIES OF

UNIFIED THEORY OF COGNITION See

PROBLEM-SOLVING AND CREATIVITY

STAGE THEORIES

UNIFIED THEORY OF SOCIAL

PSY-CHOLOGY See INFORMATION

INTE-GRATION THEORY

UNIFORMITY OF NATURE THEORY

See FINAL THEORY

UNIFYING THEORY OF

DEVELOP-MENT See DEVELOPMENTAL THEORY

UNILINEAL/UNILINEAR THEORY See

RECAPITULATION THEORY/LAW

UNIT HYPOTHESIS See

GENERALIZA-TION, PRINCIPLES OF

UNIVERSALISM, DOCTRINE OF See

MIND/MENTAL STATES, THEORIES OF

UNIVERSALISTIC THEORIES See

WORK/CAREER/OCCUPATION, RIES OF

THEO-UNIVERSAL LAW OF TION The American psychologist/cognitive

GENERALIZA-scientist Roger N Shepard (1929- ) proposed

a universal law of generalization for

psycho-logical science that attempts to advance a principle in psychology that is comparable in generality to the English physicist and mathematician Sir Isaac Newton’s (1642-

1727) universal law of gravitation in physics

The new law is based on the assumption that because any object or situation experienced by

an individual is unlikely to recur in exactly the same form and context, psychology’s first

general law should be a law of generalization

Historically, learning theorists supposed that a

principle of conditioning (via the mechanisms

of reinforcement and/or contiguity) could be

the primary principle, and where what is

learned then generalizes to new situations (left

open for later formulation) could be a dary principle Over 2,000 years ago, the

secon-Greek philosopher Aristotle (384-322 B.C.)

recognized - via his principle of association

by resemblance - that similarity is

fundamen-tal to menfundamen-tal processes, but it was not until the beginning and middle of the 20th century that experimental investigations were conducted

on the issue of generalization/similarity of

stimuli - first by Ivan Pavlov in the 1920s; then by Norman Guttman, H I Kalish, and Roger N Shepard in the 1950s; cf., Mostofsky (1965) Shepard suggests that humans general-

ize from one situation to another not because

they cannot tell the difference between the two situations, but because they judge that the situations are likely to belong to a set of situa-

tions having the same consequences alization - that arises from uncertainty about

Gener-the distribution of consequential stimuli in

“psychological space” - is to be distinguished

from failure of discrimination - that arises

from uncertainty about the relative locations

of individual stimuli in that space

Accord-ingly, in his universal law of generalization

for psychological science, Shepard posits the

notion of a “psychological space” for any set

of stimuli by determining metric distances

between the stimuli such that the probability

that a response learned to any stimulus will

generalize to any other is an invariant

mono-tonic function of the distance between them

This probability of generalization, to a good

approximation, decays exponentially with this

distance, and does so in accordance with one

of two metrics, depending on the relation

be-tween the dimensions along which the stimuli

vary Shepard asserts that these empirical

regularities are mathematically derivable from

universal principles of natural phenomena and

probabilistic geometry that may – via

evolu-tionary internalization - tend to govern the

behaviors of all sentient organisms Shepard

suggests that psychological science

undoubt-edly has lagged behind physical science by at

least 300 years and, just as likely, predictions

of behavior may never attain the precision for

animate bodies/entities that it has for celestial

bodies However, psychology inherently may

not be limited merely to the descriptive

char-acterization of the behaviors of particular

terrestrial species, but possibly - behind the

diverse behaviors of humans and animals, as

behind the various motions of planets and

stars - one may eventually discern the

opera-tion of universal laws See also

ASSOCIA-TION, LAWS/PRINCIPLES OF;

GENER-ALIZATION, PRINCIPLES OF

REFERENCES

Newton, I (1687) Philosophiae naturalis

principia mathematica London:

Royal Society

Mostofsky, D I (Ed.) (1965) Stimulus

gen-eralization Stanford, CA: Stanford

University Press

Shepard, R N (1987) Toward a universal

law of generalization for

psycho-logical science Science, 237,

1317-1323

UNIVERSAL LAW OF GRAVITATION

See UNIVERSAL LAW OF TION

GENERALIZA-UNIVERSAL MODEL OF HUMAN EMOTIONS The American neurologist/

physician Antonio R Damasio (1994)

devel-oped a universal model of human emotions

that is based on a rejection of the Cartesian

mind-body dualism, and is founded on

neuro-psychological studies and experiments The model begins with the assumption that human knowledge consists of dispositional represen-tations stored in the brain (where “thought” is the process by which such representations are ordered and manipulated) One of the repre-sentations is of the body as a whole and is based on information from the endocrine and peripheral nervous systems In his model,

Damasio defines emotion as the combination

of a mental evaluative process (simple or complex) with dispositional responses to that process, resulting in an emotional body state - but also toward the brain itself (e.g., via neu-rotransmitter nuclei in the brain stem) In dis-tinguishing “emotions” from “feelings,” Damasio states that the brain is continually monitoring changes in the body, and suggests that people “feel” an emotion when they ex-perience such changes in juxtaposition to the mental images that initiated the cycle The model distinguishes, also, between “primary emotions” (innate) and “secondary emotions” (feelings allowing one to form systematic connections between categories of objects and situations) Damasio suggests that the neuro-logical mechanisms of emotion and feeling evolved in humans in order to create strong biases to situationally-appropriate behaviors that do not require conscious thought; he ar-gues that the time-consuming process of ra-tional thought may decrease one’s chances of survival in situations that require instant deci-sions See also EMOTIONS, THEORIES/ LAWS OF; MIND-BODY THEORIES

REFERENCE

Damasio, A R (1994) Descartes’ error:

Emotion, reason, and the human brain New York: Putnam

UNLEARNING HYPOTHESIS See

IN-TERFERENCE THEORIES

UNREADINESS, LAW OF See

READI-NESS, LAW OF

UNREALISTIC OPTIMISM EFFECT

This phenomenon, and its related aspects,

studied by the American psychologists

Freder-ick Hansen Lund (1894-1965), Albert Hadley

Cantril (1906-1969), and Neil David

Weinstein (1945- ), among others, refers to a

judgmental bias in humans that tends to

influ-ence their subjective estimates of the

likeli-hood of certain future events in their own lives

as compared to others, especially their peers

For example, the unrealistic optimism effect

demonstrates that people overestimate the

likelihood in their lives of positive/desirable

events (e.g., the possibility of their living to be

older than 80 years of age), and underestimate

the likelihood in their lives of

negative/unde-sirable events (e.g., the possibility of having a

heart attack before they are 50 years old)

Studies on this issue indicate that cognitive,

motivational, and social factors such as degree

of desirability, perceived probability, personal

experience, ego-centrism, perceived

control-lability, and stereotype salience all tend to

affect the amount of optimistic bias evoked by

different possible events in people’s lives See

also DECISION-MAKING THEORIES;

OVERCONFIDENCE EFFECT

REFERENCES

Lund, F H (1925) The psychology of belief

Journal of Abnormal and Social

Psychology, 20, 63-81, 174-195

Cantril, A H (1938) The predicton of social

events Journal of Abnormal and

Social Psychology, 33, 364-389

Weinstein, N D (1980) Unrealistic optimism

about future life events Journal of

Personality and Social Psychology,

USE, LAW OF This principle is one of the

corollaries of the American psychologist

Ed-ward Lee Thorndike’s (1874-1949) law of exercise, which states that behaviors, stimu-

lus-response connections, and functions that are exercised, rehearsed, or practiced are strengthened as compared to those behaviors, bonds, or functions that are not used Some early writers held that the repeated use of a stimulus-response connection unit (neurons) bring about certain synaptic changes that made the passage of the nerve impulse more rapid in the future For example, in 1926 A Gates called this native capacity of nervous

structure modifiability the law of modification

by exercise or, more simply, the law of use [cf., the use/disuse, use-inheritance theory

advanced by the French naturalist/evolutionist Jean-Baptiste Pierre Antoine de Monet La-marck (1744-1829), which holds that the structural or functional changes in organs

brought about by their use or disuse are passed

onto the progeny) The notion of a cal change in nervous structure during the practice (use) of stimulus-response connec-tions anticipated the Canadian psychologist Donald Olding Hebb’s (1904-1985) later con-ceptualizations in perception and learning of

physiologi-cell assembly and phase sequence, where

groups of neurons are functionally interrelated and organized into a complex “closed circuit” created by repeated stimulation of those units See also DISUSE, LAW/THEORY OF; EF-FECT, LAW OF; EXERCISE, LAW OF; FREQUENCY, LAW OF; HEBB’S THEORY

OF PERCEPTUAL LEARNING; MARCK’S THEORY

LA-REFERENCES

Thorndike, E L (1898) Animal intelligence

New York: Macmillan

Gates, A (1926) Elementary psychology

New York: Macmillan

Trowbridge, M., & Cason, H (1932) An

ex-perimental study of Thorndike’s

theory of learning Journal of eral Psychology, 7, 245-258 Hebb, D O (1947) Organization of behavior

Gen-New York: Wiley

Hebb, D O (1972) Textbook of psychology

Philadelphia, PA: Saunders

US-VERSUS-THEM EFFECT See

IN-GROUP BIAS THEORIES; PREJUDICE, THEORIES OF

UTERINE THEORY See

PSYCHOPA-THOLOGY, THEORIES OF

UTILITARIANISM, THEORY OF See

REFLEX ARC THEORY/CONCEPT

UTILITY THEORY See

DECISION-MAKING THEORIES; ELICITED VING RATE HYPOTHESIS; EXPECTED UTILITY THEORY; HEDONISM, THE-ORY/LAW OF; LOGAN’S MICROMOLAR THEORY

OBSER-UZNADZE/DELBOEUF ILLUSIONS See

APPENDIX A

VALENCE-INSTRUMENTALITY-EX-PECTANCY THEORY See

WORK/CAR-EER/OCCUPATION, THEORIES OF

VALIDITY/RELIABILITY See

NOMO-LOGICAL NETWORK THEORY

VALUE THEORY See

DECISION-MAK-ING THEORIES; MEINONG’S THEORIES

VANDENBERGH EFFECT See

OLFAC-TION/SMELL, THEORIES OF

VASCULAR THEORY See NAFE’S

THEORY OF CUTANEOUS SENSITIVITY

VEATCH’S THEORY OF HUMOR This

humor theory, proposed by Thomas C Veatch

(1998), states that humor is characterized fully

by certain conditions that individually are

necessary, and are jointly sufficient, for the

humor experience to occur The conditions of

Veatch’s theory of humor involve a subjective

state of apparent emotional absurdity where

the perceived situation is viewed as normal

and where, simultaneously, some affective

commitment of the perceiver (to the way

something in the situation ought to be) is

vali-dated Thus, according to this approach,

hu-mor occurs when one views a situation

simul-taneously as being normal, as well as

consti-tuting a violation of the “subjective moral

order” where such an order is defined as the

set of principles to which the person both has

an affective commitment and a belief that he

or she ought to hold those principles Veatch

explores the logical properties and empirical

consequences of his theory, reviews the

widely-recognized aspects and features of

humor (e.g., incongruity, surprise, aggression,

emotional transformation), suggests practical

applications of his theory, and accounts for a

wide variety of biological, tional, and other categories/classes of humor-related phenomena See also HUMOR, THE-ORIES OF; INCONGRUITY/INCONSIS-TENCY THEORIES OF HUMOR; SUR-PRISE THEORIES OF HUMOR

social-communica-REFERENCE

Veatch, T C (1998) A theory of humor

mor: International Journal of mor Research, 11, 161-215

Hu-VENABLE’S COLOR VISION THEORY

See COLOR VISION, THEORIES/LAWS

VERBAL DEPRIVATION HYPOTHESIS

See CHOMSKY’S PSYCHOLINGUISTIC THEORY

VERBAL LOOP HYPOTHESIS See

CHOMSKY’S PSYCHOLINGUISTIC ORY

THE-VERBAL TRANSFORMATION EFFECT

See APPENDIX A

VIBRATION/VIBRATIONAL THEORY

See OLFACTION/SMELL, THEORIES OF

VIBRATORY THEORY OF ANCE See MENDEL’S LAWS/PRIN-

INHERIT-CIPLES

VICARIOUS BRAIN PROCESS POTHESIS See LASHLEY’S THEORY VICTIM PRECIPITATION HYPOTHE- SIS See LOMBROSIAN THEORY

HY-VIERORDT’S LAW OF TIME TION See VIERORDT’S LAWS

ESTIMA-VIERORDT’S LAWS There are two

sepa-rate usages or versions subsumed under the

same eponymic principle called Vierordt’s law, both of which are attributable to the

German physiologist Karl von Vierordt

(1818-1884) One usage is related to the study of

sensory thresholds, and the other usage refers

to the area of time perception In the first case,

Vierordt’s law is the proposition that the more

moveable a part of the body is, the lower is

the two-point threshold of the skin over it

Thus, the two-point threshold decreases (i.e.,

increased tactile acuity) as one goes from the

acromion/shoulder blade to the tips of the

fingers In other terms, Vierordt’s law of

out-ward mobility in the area of sensory

psychol-ogy states that tactile acuity increases with

increased mobility of body members

How-ever, although Vierordt’s outward mobility

law appears to be true, generally, for the upper

extremity, it is not as clearly applicable to

various other body areas (cf., Greenspan &

Bolanowski, 1996) In the second case,

Vierordt’s law of time estimation is the

princi-ple that short temporal intervals tend to be

overestimated and long temporal intervals

tend to be underestimated Also, in this

con-text of time perception/estimation, the concept

of the in-difference interval is defined as the

intermediate length of time that is neither

underestimated nor overestimated Based on

this early general law of time estimation by

Vierordt in the late 1800s, subsequent

re-search in the area of the psychology of time

has determined that the overestimation of

short durations and the underestimation of

long ones is as valid for “filled”

tions/intervals as for “empty”

dura-tions/intervals Thus, in turn, and ground-ed in

Vierordt’s law of time estimation,

psycholo-gists today study the effect of the different

forms of “filling” a temporal interval (ranging

from the use of short, discrete auditory tones

to long, more continuous and meaningful

nar-ratives/events/materials) on one’s perceived

duration and estimation of time See also

FRAISSE’S THEORY OF TIME;

GUY-AU’S THEORY OF TIME; SOMESTHESIS,

THEORIES OF; TIME, THEORIES OF

REFERENCES

Vierordt, K von (1868) Der zeitsinn nach

versuchen Tubingen, Germany: H

Laupp

Vierordt, K von (1870) Abhangigkeit der

ausbildung des raumsinnes der haut

von den beweglichkeit der

korpert-heile Zeitschrift fur Biologie, 6,

53-72

Greenspan, J D., & Bolanowski, S J (1996)

The psychophysics of tactile tion and its peripheral physiological

percep-basis In L Kruger (Ed.), Pain and touch San Diego, CA: Academic

Press

VIGILANCE, THEORIES OF = sustained

attention theories In general, theories of lance refer to the systematic accounts of how observers maintain their focus of attention

vigi-(i.e., the selective aspects of perception that function to help an organism focus on certain features of the environment to the exclusion of other features) and remain alert to stimuli over

prolonged periods of time [i.e., sustained tention; cf., the law of prior entry - the princi-

at-ple that if a participant is attending to one of two possible stimuli and, if they occur simul-taneously, the one to which he/she is attending

tends to be perceived as having occurred fore the other; in social/personality psychol- ogy, this is called the prior entry effect where

be-the first impression(s) one has of anobe-ther son tend to be the dominate one(s) and are not easily changed by further acquaintance; cf.,

per-also, laws of attention (Woodworth, 1921): selection - of two or more inconsistent re-

sponses to the same situation, only one is

made at the same time; advantage - one of the

alternative responses has an initial advantage over the others due to such factors as intensity and change in the stimulus, or to habits of

reaction; shifting - the response that has the

initial advantage loses its advantage shortly and an alternative response is made, provided

the situation remains the same (cf., the law of shifting, proposed by the American psycholo-

gist Edward Lee Thorndike, which states that

it is relatively easy to elicit a response that an organism is capable of performing in any situation - and to which it is sensitive - and, thereby, form an association between the re-

sponse and the features of that situation); dency - a predisposition when aroused to ac-

ten-tivity facilitates responses that are in its line

and inhibits others; and combination - a single

response may be made to two or more stimuli, and two or more stimuli may arouse a single

joint response] The various specific theories

and models of vigilance attempt to deal with

certain common questions in an observer’s

behavior during a vigilance task: How is

back-ground information stored? How are decisions

made during observation? and How do neural

attention units function? A sampling of the

vigilance theories and some of their major

tenets are: expectancy theory - observers act

as “temporal averaging instruments” who

form expectancies as to the approximate time

course of critical signal appearances on the

basis of samples of signal input; readiness to

detect a signal is assumed to be positively

related to level of expectancy; elicited

observ-ing rate hypothesis - the observer constantly

makes sequential decisions about whether or

not to emit observing responses toward the

display that is monitored; detection failures

occur when the participant does not emit the

observing responses due to fatigue or low

motivation or does so in an imperfect fashion;

signal detection theory - the decrement

func-tion typically found in a vigilance task reflects

a shift to a more conservative response

crite-rion and decision process, rather than a

de-cline in alertness or perceptual sensitivity to

signals; activation/arousal theory - instead of

a “cognitive” appraisal of vigilance, this

ap-proach emphasizes a neurophysiological

ex-planation whereby sensory input has two

gen-eral functions: to convey information about

the environment and to “tone up” the brain

with a background of diffuse activity that

helps cortical transmission via increased

alert-ness; this orientation suggests that the

mo-notonous aspects of vigilance tasks reduce the

level of nonspecific activity that is necessary

to maintain continued alertness and,

conse-quently, lead to a decline in the efficiency of

signal detection; and habituation theory -

habituation is a lessening of neural

respon-siveness due to repeated stimulation and is an

“active process of inhibition;” this approach

argues that the degree of neural habituation in

a given task is directly related to the frequency

of stimulus presentation so that with the

de-velopment of habituation the observer’s

abil-ity to discriminate critical signals is degraded,

attention to the task becomes increasingly

more difficult, and performance declines over

a period of time; this theory holds that

ha-bituation accumulates more rapidly at fast,

than at slow, rates and results in a decline in performance at fast stimulus/event rates The

current status of vigilance theories is that each

model focuses on a somewhat different aspect

of the sustained attention situation, even though many theories can account for similar data To date, the task remains of synthesizing the various theoretical positions of vigilance into a unified framework where stronger “law-ful” cause-effect statements may be provided See also ACTIVATION/AROUSAL THE-ORY; ATTENTION, LAWS/PRINCIPLES OF; ELICITED OBSERVING RATE HY-POTHESIS; HABITUATION, PRINCIPLE/ LAW OF; IMPRESSION FORMATION, THEORIES OF; REINFORCEMENT, THORNDIKE’S THEORY OF; SIGNAL DETECTION THEORY

REFERENCES

Woodworth, R S (1921) Psychology: A

study of mental life New York:

Holt

Deese, J (1955) Some problems in the theory

of vigilance Psychological Review,

62, 359-368

Baker, C (1963) Further toward a theory of

vigilance In D Buckner & J

McGrath (Eds.), Vigilance: A posium New York: McGraw-Hill Davies, D., & Tune, G (1969) Human vigi-

sym-lance performance New York:

American Elsevier

Mackworth, J (1969) Vigilance and

habitua-tion Baltimore: Penguin Books Stroh, C (1971) Vigilance: The problem of

sustained attention New York:

Per-gamon

Mackie, R (Ed.) (1977) Vigilance: Theory,

operational performance, and iological correlates New York:

phys-Plenum

Parasuraman, R., & Davies, D (1989)

Varie-ties of attention Orlando, FL:

VISION/SIGHT, THEORIES OF One of

the earliest theories that attempted to describe

a mechanism for human vision was proposed

by the Greek mathematician/mystic

Pythagor-as (c 582-507 B.C.) He Pythagor-asserted that rays of

light sprang from the eyes themselves, much

like twin spotlights; somehow, the light

strik-ing objects in front of the observer triggered a

reaction in the eye, and vision was the result

However, by the 15th century, Pythagoras’

theory was reversed, where the eyes were

considered the receivers, not senders, of light

By that time, some of the greatest scientists of

the say began to investigate the question of

light’s influence on the eye For example,

Leonardo da Vinci (1452-1519) made detailed

drawings of the eye’s anatomy; Johannes

Ke-pler (1571-1630) formulated the basic laws of

light refraction, which explained how light

rays can be bent as they travel from one

me-dium to another; and Rene Descartes

(1596-1650) conducted studies concerning the

appli-cation of these refraction laws to the structural

features of the eye, which led to a basic

under-standing of how the eye focused incoming

light [cf., Maxwellian view - named after the

Scottish physicist James Clerk Maxwell

(1831-1879), refers to the elimination of light

fluctuations entering the eye due to pupil size

fluctuations by concentrating light coming off

an object by the use of a spherical, or

“fish-eye,” lens to focus light in the pupil’s plane]

By 1666, Sir Isaac Newton’s (1642-1727)

experiments on the composition of light itself

was the formal beginning of inquiries into the

physical nature of light as well as inquiries

into the way the eye interprets color

phenom-ena [cf., the inverse square law - the principle

that the intensity of a stimulus that reaches the

receptor from a distant source varies inversely

as the square of the distance of the source

from the receptor (Note: In the context of

inferential statistics, the inverse square law is

the principle that the sampling error tends to

be inversely proportional to the square root of

the sample size); the law of illumination - the

principle that the illumination upon a surface

varies directly as the luminous intensity of the

light source, inversely as the square of its

distance, and directly as the cosine of the

an-gle made by the light rays with the

perpen-dicular to the surface; and the Arago

phe-nomenon - named after the French astronomer

and physicist Francois Arago (1786-1853), is the relative insensitivity to light of the very center of the visual field at very low levels of

illumination] According to modern vision theory, the stimulus for the sensory modality

of vision/sight is electromagnetic radiation (light) between approximately 380 and 740

nanometers (nm, where 1 nm = 1 billionth of a

meter), and where the initial processing of visual information is the receptor system con-

sisting of photosensitive cells (rods and cones)

in the retina of the eye Vision is the process

of transforming (“transducing”) physical light energy into biological neural impulses that can then be interpreted by the brain The electro-

magnetic radiation can vary in intensity ceived as a difference in brightness level) and wavelength (perceived as a difference in hue

(per-or “col(per-or”) The quantum the(per-ory of vision

maintains that light energy travels to the eye

in the form of discrete or discontinuous changes in energy where wavelength frequen-cies correspond to definite energies of the

light quanta called photons The Dutch

physi-cist Christiaan Huygens (1629-1693) first

proposed the undulatory theory, which forms

a part of the wave theory of light that planted the earlier corpuscular/particle the- ory The wave theory offers a ready explana-

sup-tion of interference, diffracsup-tion, and tion of light but fails to explain the interaction

polariza-of light with matter, the emission and tion of light, photoelectricity, and other phe-nomena These can be explained only by a

absorp-quasi-corpuscular theory involving packets of energy - light quanta or photons The quantum theory was introduced by the German physi-

cist Max Planck (1858-1947) in 1900 mately, it appears that two models are re-quired to explain the phenomenon of light

Ulti-According to the complementarity principle of

the Danish physicist Niels Bohr (1885-1962),

a system such as an electron can be described

either in terms of particles or in terms of wave motion Theories of vision are systematic at-

tempts to account for the various phenomena

of visual perception in relation to the known structure and functions of the visual organs Included by extension is the study of photore-ceptors; the action of nerves and nerve end-

ings [cf., Hering’s law of equal innervation -

named after the German physiologist Karl

Ewald Hering (1834-1918), states that the

muscles of each eye always operate in

syn-chrony because they receive the same

innerva-tion; the study of responses to light in lower

organisms; the higher psychological

implica-tions of light, color, form, and their temporal

and spatial relations (cf., Harvey’s principle -

when a grating is viewed, the number of

verti-cal stripes per unit of total breath is

overesti-mated and the number of horizontal stripes is

underestimated; Leonardo’s paradox - named

after the Italian artist/scientist Leonardo da

Vinci (1452-1519), refers to da Vinci’s

asser-tion that it is not possible to reproduce via a

painting what a person sees binocularly,

be-cause in binocular vision, each eye sees

some-thing that the other eye does not see; Hering’s

law of identical visual direction - in binocular

vision, any pair of corresponding lines of

di-rection in objective space are represented by a

single line of direction in visual space; and the

superposition hypothesis - the binocular vision

of newborn infants blends together the

mo-nocular visual responses of the two eyes, even

when the visual stimulus evokes binocular

rivalry in adults, and suggests that such

blend-ing is replaced by binocular rivalry after the

development/emergence of stereopsis at about

age 8-12 weeks old (cf., Brown & Miracle,

2003) In his computational theory of vision,

the English psychologist David C Marr

(1945-1980) makes a formal analysis of

per-ception that is based on a theory of vision that

attempts to explain how the pattern of light

falling on the retinas of the eyes is

trans-formed into an internal representation of the

colors, shapes, and movements of what is

observed; three stages are involved in the

process: the “primal sketch,” the

“two-and-one-half dimensional sketch,” and the

“three-dimensional model” description The

ana-tomical and physiological basis for vision may

be hypothesized much as is the case for the

theories of color vision; for example, the

three-component Young-Helmholtz theory; the

antagonistic/opponent-process theory of

Her-ing; the Ladd-Franklin genetic theory; and the

von Kries duplicity theory The cone cells

(“daylight vision”) in the retina are

responsi-ble for chromatic/color vision and visual

acu-ity [cf., Charpentier’s law - named after the

French physician Augustin Charpentier 1916), states that in the retinal fovea, the product of the area of a stimulus and its inten-sity is constant for stimuli at threshold intensi-

(1852-ties; Charpentier bands - illusory black spokes

that may be seen when a black disk with a

white sector is rotated slowly; the blue-arc phenomenon - an effect produced by a stimu-

lus at the center of the visual field against a dark background; it consists of a pair of blu-ish, luminous arcs seen as connecting the stimulus with the locus of the blind spot; the

Troxler fading/effect - named after the

Swiss-German physician/philosopher Ignaz P V Troxler (1780-1866), is the fading of visual objects in the periphery of the visual field when a point in its center is steadily fixated; this is due to the organization of the peripheral retina, which requires larger eye movements than are needed in the fovea, to break the ad-aptation brought about by steady fixation; the

Ditchburn-Riggs effect - named after the

Eng-lish physicist Robert William Ditchburn (1903-1987) and the American psychologist Lorin A Riggs (1912- ), is the phenomenon

of the rapid cessation of the vision of contours when the image of the contours undergoes prolonged stabilization with respect to the

retina; and the Rayleigh equation - named

after the English physicist Lord J W S Rayleigh (1842-1919), is an index of one’s color vision given by the proportion of light from the red and green portions of the visible spectrum that need to be mixed to make a

standard yellow] The rod cells (“night-time

vision”) are sensitive to minute amounts of light but are not sensitive to colors (cf., Ka-

neko’s photochemical theory of vision)

Be-cause of the anatomical features of the visual

system, the left visual field is represented in the right occipital lobe of the brain, and the right visual field is represented in the left oc-

cipital lobe It is much easier to trace cally the visual pathway from the retina to the occipital lobes than it is to explain and under-stand how the eyes and the brain interact to

anatomi-produce the perception of vision (cf., mind’s eye theory - proposes an as-yet-unidentified

neurological structure located in the brain where visual information obtained from the two eyes or from long-term memory is stored temporarily while being processed as a visual

image, allowing one to reason from visual

images; the Cheshire cat effect - relies on the

phenomenon of binocular rivalry, where each

eye has a different input from the same part of

the visual field, and where motion in the field

of one eye can cause either the entire image to

disappear or parts of the image to be erased;

the movement captures the brain’s attention

momentarily; this effect is named after the

Cheshire cat in Lewis Carroll’s “Alice’s

Ad-ventures in Wonderland” where the cat

van-ishes slowly, beginning with the end of its tail

and ending with its grin that remained some

time after the rest of the cat had disappeared)

More is known about how photochemical

processes and mechanisms operate in the rod

cells than about the cone cells In addition to

responding directly to light, the receptor cells

are affected, also, by the surrounding receptor

cells Studies have shown that there are both

inhibitory and excitatory effects when

neighboring receptor cells fire simultaneously

Other studies indicate that various cells in the

visual cortex are maximally activated by

ob-jects in the visual field with specific shapes, of

particular orientations, and moving in

particu-lar directions For instance, D Hubel and T

Wiesel hypothesize the existence of four

gen-eral types of hierarchically organized cells

(simple, complex, lower-order hypercomplex,

and upper-order hypercomplex), and this

no-tion has found anatomical support from other

research, but the theory that those cells are

arranged hierarchically is not yet supported

Over 100 years ago, the German physican and

psychologist Hermann Aubert (1826-1892)

provided a number of theoretical and lawful

propositions concerning visual acuity and

perception; cf., Listing’s law of visual

ac-commodation - named after the German

phy-sicist Johann Benedict Listing (1808-1882),

refers to the case where, if the eye moves from

a primary position to any other position, the

torsional rotation of the eyeball in the new

position is the same as it would be if the eye

had turned about a fixed axis, and lies at right

angles to the initial and final directions of the

line of regard; and Alexander’s law - named

after the Austrian otologist Gustav Alexander

(1873-1932), refers to nystagmus, produced

either by rotation or thermally, that can be

accentuated voluntarily by moving the eyes in

the direction of the jerky component of the nystagmus Among Aubert’s eponymous ref-

erents are the following: the Aubert-Fleischl paradox/phenomenon - named after Aubert

and the Austrian physiologist Marxow Ernst Fleischl (1846-1891), is a perceptual effect whereby a moving stimulus seems to move more slowly when the observer fixates on the stimulus than when she or he fixates on the

background; the Aubert-Forster phenomenon -

named after Aubert and the Polish-born man ophthalmologist Carl F R Forster (1825-1902), refers to the situation where two ob-jects of different physical sizes are placed at different distances from the observer such that both subtend the same number of degrees of visual arc, the physically closer one can be recognized over a greater area of the retina

Ger-than the physically more distant one; the bert phenomenon - refers to the case where a

Au-single vertical straight-line stimulus is sented to an observer, and the line is displaced perceptually as the observer tilts his/her head

pre-(cf., the Muller effect - named after the

Ger-man psychologist Georg Elias Muller 1934), refers to the case where an observer views a luminous vertical rod in the dark, and

(1850-it appears to be tilted out of vertical in the same direction as the head; this effect occurs

only with small tilts of the head); and the bert-Forster law - a generalization regarding visual acuity based on the Aubert-Forster phenomenon that states that objectively small

Au-objects can be distinguished as two at greater distances from the fovea than objectively lar-ger objects subtending the same visual angle

(cf., the Alice in Wonderland effect - is a

vis-ual defect where one sees things as smaller than they are in actuality; in a clinical context,

the Alice in Wonderland syndrome refers to

depersonalization and “Lilliputian tions,” that is, hallucinations involving objects that appear to be extremely small, derived

hallucina-from Jonathan Swift’s (1726) novel, ver’s Travels in which the imaginary country

Gulli-of Lilliput has inhabitants who are only six

inches tall; and associative/ geometric illusion

- a visual misperception in which one part of

an object or image is viewed erroneously due

to the effect of another object/image;

Appen-dix A provides a listing of various visual sions/effects) See also ADAPTATION,

illu-PRINCIPLES/LAWS OF; ATTENTION,

LAWS/PRINCIPLES/ THEORIES OF;

COLOR VISION, THEORIES/LAWS OF;

DOPPLER EFFECT/PRIN-CIPLE/SHIFT;

IMAGERY/MENTAL IMAGERY,

THEO-RIES OF; NORMAL DISTRIBUTION

THE-ORY; PERCEPTION (I GENERAL),

THEORIES OF; PERSONAL EQUATION

PHENOMENON; PURKINJE

EF-FECT/PHENOMENON/SHIFT

REFERENCES

Aubert, H (1865) Physiologie der netzhant

Breslau: Morgenstern

Aubert, H (1866) Die

bewegungsempfin-dung Archiv fur die Gesamte

Phy-siologie, 39, 347-370

Stratton, G M (1897) Vision without

inver-sion of the retinal image

Psych-ological Review, 4, 341-360

Luckiesh, M (1922/1965) Visual illusions:

Their causes, characteristics, and

applications New York: Van

Nostrand/Dover

Sharp, W L (1928) The floating-finger

illu-sion Psychological Review, 35,

171-173

Hartline, H., & Ratliff, F (1957) Inhibitory

interaction of receptor units in the

eye of limulus Journal of General

Physiology, 40, 357-376

Hubel, D., & Wiesel, T (1965) Receptive

fields and functional architecture in

two nonstriate visual areas (18 and

19) of the cat Journal of

Neuro-physiology, 28, 229-289

Kelly, J., & VanEssen, D (1974) Cell

struc-ture and function in the visual cortex

of the cat Journal of Physiology,

238, 515-547

Gregory, R (1978) Eye and brain: The

psy-chology of seeing New York:

McGraw-Hill

Kaneko, A (1979) Physiology of the retina

Annual Review of Neuroscience, 2,

169-191

Marr, D C (1982) Vision San Francisco: W

H Freeman

Bundesen, C (1991) A theory of visual

atten-tion Psychological Review, 97,

523-547

Harris, M., & Humphreys, G (1994)

Compu-tational theories of vision In A

Colman (Ed.), Companion pedia of psychology London: Rout-

encyclo-ledge

Crick, F., & Koch, C (1997) The problem of

consciousness In Scientific can (Special Issue), Mysteries of the mind Vol 7 No 1

Ameri-Brown, A., & Miracle, J (2003) Early

bin-ocular vision in human infants: Limitations on the generality of the

superposition hypothesis Vision search, 43, 1563-1574

VISUOSPATIAL SKETCHPAD OR SCRATCHPAD MODEL See WORKING

MEMORY, THEORY OF

VITAL FLUIDS THEORY See LIFE,

THEORIES OF

VITALISM THEORY See HOBBES’

PSYCHOLOGICAL THEORY; LIFE, ORIES OF; LOEB’S TROPISTIC THEORY; MECHANISTIC THEORY

THE-VITAMIN MODEL OF EMPLOYEE SATISFACTION See WORK/CAREER/

OCCUPATION, THEORIES OF

VIVIDNESS/CLEARNESS, LAW OF See

ASSOCIATION, LAWS/PRINCIPLES OF

VOLLEY/PERIODICITY THEORY AND VOLLEY PRINCIPLE See AUDITION/

HEARING, THEORIES OF

von DOMARUS PRINCIPLE See

SCHI-ZOPHRENIA, THEORIES OF

von FREY’S FOUR-ELEMENT

THEO-RY See SOMESTHESIS, THEORIES OF von KRIES’ COEFFICIENT LAW In the

context of the phenomenon of chromatic aptation (i.e., conditions where a colored

ad-stimulus is viewed following adaptation to

another color and differs in appearance from

the same stimulus seen without pre-exposure

and, conversely, where numerous pairs of

colors that ordinarily differ may look alike

when they are viewed by eyes that have been

previously adapted to different kinds of light),

the von Kries coefficient law - named after the

German physiologist Johannes von Kries

(1853-1928) - states that the tri-stimulus

val-ues of all colors for one condition of

adapta-tion bear fixed ratios to the corresponding

tri-stimulus value for the visually equivalent

colors observed under another condition of

adaptation However, in one case, D L

Mac-Adam notes that his own experimental

hy-potheses - based on von Kries’ law - were not

supported Consequently, MacAdam

hypothe-sizes the existence of different receptors

whose responses are merged onto three

chan-nels in the nervous system: the so-called

“tri-chromatic mechanism.” See also

ADAPTA-TION, PRINCIPLES/LAWS OF; COLOR

VISION, THEORIES/LAWS OF; von

KRIES’ COLOR VISION THEORY; ZONE/

STAGE THEORIES OF COLOR VISION

REFERENCES

Kries, J von (1905) Die

gesichtsempfindun-gen In W Nagel (Ed.), Handbuch

der physiologisches menchens

Braunschweig: Vieweg

MacAdam, D L (1956) Chromatic

adapta-tion Journal of the Optical Society

of America, 46, 500-513

von KRIES’ COLOR VISION THEORY =

duplicity/duplexity theory The

duplicity/du-plexity theory of vision was first proposed by

Max Schultz in 1866, and later by H Parinaud

and the German physiologist Johannes von

Kries (1853-1928) The theory states that

vi-sion is mediated by two (“duplex”) classes of

retinal receptors, the cones that are

“chro-matic” and sensitive to color wavelengths and

used in high illumination (“photopic vision”),

and the rods that are “achromatic” and used in

low illumination (“scotopic vision”) Because

the two classes of receptors manifest different

wavelength relationships, the shape of a

spe-cific function that relates brightness to color

may be used to indicate whether rod or cone

vision is predominant in a given situation [cf.,

the Anglo-American psychologist William

McDougall’s (1871-1938) early color vision theory that states that there are two distinct

receptor mechanisms for light in the retina: rods for dim light and cones for normal and intense light; the theory holds, also, that all colors are reducible to the three basic colors of blues, greens, and reds] There are anatomical

differences between the rods and cones, even

though these two types of receptors are very similar: (1) the rods are smaller and seem to

be less highly developed than the cones; (2) there are no rods (only closely packed cones)

in the foveal area of the retina; (3) the cones have a better (“one-to-one”) supply of nerves; (4) the substance rhodopsin (“visual purple”)

is present in the rods but not in the cones; and (5) nocturnal animals possess mostly rods and

very few cones Today, the von Kries duplicity theory of vision is so well established that it

counts as a strong statement of fact See also COLOR VISION, THEORIES/LAWS OF; FOVEAL CONE HYPOTHESIS; von KRI-ES’ COEFFICIENT LAW

REFERENCES

Schultze, M (1866) Zur anatomie und

physi-ologie der retina Archiv der roskopische Anatomisch, 2, 175-

Mik-286

Kries, J von (1895) Uber die natur gewisser

mit den psychischen vorgangen

ver-knupfter gehirnzustande Zeitschrift fur Psychologie, 8, 1-33

Parinaud, H (1898) La vision Paris: Octave

Doin

von KRIES’ DUPLICITY THEORY See

VISION/SIGHT, THEORIES OF; von KRIES’ COLOR VISION THEORY

von KRIES-SCHRODINGER ZONE ORY See COLOR VISION, THEO-

THE-RIES/LAWS OF

von RESTORFF EFFECT = Restorff

phe-nomenon/effect The German psychologist and physician Hedwig von Restorff (1906- ?) developed the generalization that if in a given series of stimuli to be learned (such as a list of words), one of them is made physically dis-tinctive in some way (e.g., printed in large type or in a different color from the others), it

will be easier to learn and recall This

phe-nomenon, called the von Restorff effect, and

also known as the isolation effect and the

Koh-ler-Restorff phenomenon - named after the

German psychologist Wolfgang Kohler

(1887-1967) and H von Restorff, refers to the

ten-dency to remember unusual items better than

the more common items The experiments by

H von Restorff (1933) and W Kohler and H

von Restorff (1935) provided a trace theory

basis for the Gestalt psychologists to explain

the forgetting of material A trace regarding

learned materials may become distorted

through its interactions with a mass of related

traces similar to it Thus, “associative

interfer-ence” in forgetting experiments is related to

the material to be remembered Von Restorff

showed that part of the difficulty of learning a

list of syllables stems from their homogeneity:

they are all undistinguishable and equally

confusable with one another However, if one

item is perceptually distinguishable, then that

unique item will be remembered better than

the other items Kohler and von Restorff

con-ceived of the unique item as standing out like

a figure against a ground/ background of all

the homogeneous items Being thus

distin-guished, the trace laid down for the unique

item would be isolated from the traces of the

rest of the items and, therefore, would not be

distorted by interactions with those traces

Accounts of the von Restorff effect by

stimu-lus-response associationists have proceeded

along similar lines, using principles both of

stimulus generalization and associative

inter-ference See also ASSOCIATION,

LAWS/PRINCIPLES OF; ASSOCIATIVE

FACILITATION AND INTERFERENCE

EFFECTS; GENERALIZATION,

PRINCI-PLES OF; GESTALT THEORY/LAWS;

INTERFERENCE THEORIES OF

FOR-GETTING; TOP-DOWN PROCESSING/

THEORIES; TRACE THEORY/DOCTRINE

REFERENCES

Restorff, H von (1933) Analyse von

vorgan-gen im spurenfled I Uber die

wir-kung von bereichsbildungen im

spu-renfeld Psychologische Forschung,

18, 299-342

Kohler, W., & Restorff, H von (1935)

Ana-lyse von vorgangen im spurenfeld

II Zur theorie der reproduction

Psychologische Forschung, 21,

56-112

Jensen, A (1962) The von Restorff isolation

effect with minimal response

learn-ing Journal of Experimental chology, 64, 123-125

Psy-W

WALLER’S LAW See

NEURON/NEUR-AL/NERVE THEORY

WANDERING WOMB THEORY See

PSYCHOPATHOLOGY, THEORIES OF

WARM/COLD EFFECT See

IMPRESS-ION FORMATIMPRESS-ION, THEORIES OF

WARM-UP EFFECT See PERCEPTION

(II COMPARATIVE APPRAISAL),

THEO-RIES OF; WOLPE’S

THEORY/TECHNI-QUE OF RECIPROCAL INHIBITION

WATERFALL ILLUSION/EFFECT See

APPENDIX A

WATSON’S THEORY See

BEHAVIOR-IST THEORY

WAVE THEORY OF LIGHT See VISION/

SIGHT, THEORIES OF

WEAK LAW OF EFFECT See EFFECT,

LAW OF

WEAR-AND-TEAR THEORIES OF

AG-ING See AGING, THEORIES OF

WEBER-FECHNER LAW See

FECHNER’S LAW

WEBER’S LAW = relativity law = Weber’s

fraction = Weber’s function = Weber’s ratio

The German physiologist/psychophysicist

Ernst Heinrich Weber (1795-1878) formulated

this psychophysical generalization that states

that the just-noticeable differences (or JNDs),

i.e., the differences between two stimuli that

are detected as often as they are undetected, in

stimuli are proportional to the magnitude of

the original stimulus Weber described the

relationship between existing stimulation and

changes in that stimulation in what historians

of psychology have called the first

quantita-tive law of psychology; cf., the quotient

hy-pothesis that is an interpretation of Weber’s law according to which the quotients/ratios of any two successive JNDs in a given sensory series are always equal; and Breton’s law,

which is a formula proposed by P Breton as a

substitute for Weber’s law, that posits a bolic relation between stimulus and JND In formal terms, Weber’s law states that ∆ I ⁄ I =

para-k, where I is the intensity of the comparison stimulus, ∆ I is the increment in intensity just detectable, and k is a constant The law holds

reasonably well for the mid-range of most stimulus dimensions but tends to break down when very low- or very high-intensity stimuli are used For instance, for very-low intensity

tones the Weber fraction is somewhat larger

than it is for moderately loud tones

Represen-tative values of the Weber ratio for the

inter-mediate range of some sensory dimensions are: brightness = 02 to 05; visual wave-length = 002 to 006; loudness = 1 to 2; auditory frequency = 002 to 035; taste (salt)

= 15 to 25; smell = 2 to 4; cutaneous sure = 14 to 16; and deep pressure = 01 to

pres-.03 The law of progression refers to a

formu-lation devised by the Belgian psychophysicist

J L R Delboeuf (1831-1896) as a partial

substitute for Weber’s law and states that

suc-cessive sensation increments increase by ithmetical progression when the correspond-ing stimulus-increments increase by geometric

ar-progression Delboeuf’s law of degradation, another partial substitute for Weber’s law,

states that a sensation is always strongest as it enters consciousness and from then on be-

comes less intense; and Delboeuf’s law of tension states that any change in external

stimuli produces a condition of rium/tension in the organism that constitutes the excitation whose conscious accompani-ment is the “sensation.” An indication of the

disequilib-enduring significance of Weber’s law is

pro-vided by Roeckelein (1996): in a random sample of 136 introductory psychology text-books published from 1885 through 1996,

Weber’s law is cited and described in over

60-percent of the books (an extremely high centage for all the laws found in this study), suggesting that it is one of the most popular and frequently cited laws in the psychological

per-literature E B Titchener mentions Weber’s law in more than 18 different contexts (e.g.,

Weber’s law for affection, for auditory

sensa-tions, for cutaneous sensasensa-tions, for organic

sensations, etc.) in his textbook Weber’s law

has even been applied successfully to plants’

response systems (cf., Fuller, 1934) S Smith

and E R Guthrie mention only one law in

their textbook: Weber’s law See also

FECHNER’S LAW;

FULLERTON-CAT-TELL LAW; WUNDT’S THEORIES/

DOC-TRINES/PRINCIPLES

REFERENCES

Weber, E H (1834) De pulsu, resorptione,

auditu et tactu Leipzig: Koehler

Delboeuf, J R L (1883) Elements de

psy-chophysique Liege: (Publisher

un-known)

Gamble, E (1898) The applicability of

We-ber’s law to smell American

Jour-nal of Psychology, 10, 82-142

Titchener, E B (1907) An outline of

psychol-ogy New York: Macmillan

Smith, S., & Guthrie, E R (1924) General

psychology in terms of behavior

New York: Appleton

Yoshioka, J (1929) Weber’s law in the

dis-crimination of maze distance by the

white rat University of California

Publications in Psychology, 4,

155-184

Fuller, H (1934) Plant behavior Journal of

General Psychology, 11, 379-394

Roeckelein, J E (1996) Citation of laws and

theories in textbooks across 112

years of psychology Psychological

Reports, 79, 979-998

WEDENSKY INHIBITION/EFFECT See

SKINNER’S DESCRIPTIVE BEHAVIOR/

OPERANT CONDITIONING THEORY

WEISFELD’S

ADAPTIVE/EVOLUTION-ARY/ETHOLOGICAL HUMOR

THE-ORY.Classical evolutionary theory from the

discipline areas of anthropology,

sociobiol-ogy, and ethology is applied by G E Weisfeld

(1993) to the issue of the adaptive value of

humor Weisfeld’s evolutionary humor theory

proposes that humor evolved to induce the

individual to seek out informative social

stimulation and to reward others for providing

such information His approach distinguishes

the derivative effects of humor (such as group

solidarity, competition, courtship, and tion) from the fundamental adaptive value of

relaxa-humor Weisfeld’s theory does not rest on the

traditional assumptions of humor theory cerning tension-reduction/release or pleasure-seeking; his theory avoids group-selection reasoning and it addresses the fitness benefits

con-of the humorist as well as the laugher The theory accounts for the fact that laughter is a means of social influence, and it applies to

chimpanzees as well as humans Thus, feld’s humor theory recognizes both the moti-

Weis-vational and affective properties of humor, and not just its cognitive characteristics Weis-feld’s approach helps to explain why aggres-sive, sexual, and competitive content is par-ticularly funny, why a “playful mood” is nec-essary for humor appreciation, why intelligent and socially-competent children and adults tend to make good humorists, and why the

condition of incongruity is humorous feld’s adaptive theory of humor contains ele-

Weis-ments that are consistent with existing logical explanations for various “aesthetic” emotions (such as olfaction, music apprecia-tion, and visual art appreciation), and is simi-lar, also, to leading evolutionary explanations for the behavior of “interest.” See also DAR-WIN’S EVOLUTION THEORY; HUMOR, THEORIES OF; INCONGRUITY/INCON-SISTENCY THEORIES OF HUMOR; PID-DINGTON’S COMPENSATORY HUMOR THEORY; SOCIAL/COMMUNICATION THEORY OF LAUGHTER; SULLY’S THEORY OF LAUGHTER/HUMOR

bio-REFERENCE

Weisfeld, G E (1993) The adaptive value of

humor and laughter Ethology and Sociobiology, 14, 141-169

WEISMANN’S THEORY = Weismannism

The German biologist August Friedrich pold Weismann (1834-1914) formulated a

Leo-theory of genetics that negates the principle

that acquired characteristics are inherited, and

postulated a continuity of germ plasm through

generations Weismann was a strong supporter

of Charles Darwin’s (1809-1882) theory of evolution In an attempt to disprove the idea of

acquired characteristics proposed by Baptiste Lamarck (1744-1829), Weismann amputated the tails from mice during five

Jean-successive generations and found that there

was no reduction in the propensity to grow

tails Weismann’s early work on the sex cells

and development of the Hydrozoa

(inverte-brate sea animals such as jellyfish, sea

anem-ones, hydroids) led him to develop his germ

plasm/continuity theory, which postulates that

the information required for the development

and final form of an organism must be

con-tained within the germ cells, the egg and

sperm (he located the germ plasm in what are

called today the chromosomes), and be

trans-mitted unchanged from generation to

genera-tion (cf., epigenetic theory - a universally

accepted notion that the development of an

embryo consists of the gradual differentiation

of the fertilized ovum and the separate

produc-tion/organization of structures and organs; this

approach contrasts with the theory of

prefor-mationism, or preformation, that is a

discred-ited theory stating that an embryo is fully

dif-ferentiated in the ovum or spermatozoon and

merely increases in size during development;

in a broader context, epigenetic theory

im-plies, also, that mind and consciousness

de-veloped unpredictably from living matter and

reached a high level of complexity in the

course of evolution; the theory also includes

the notion that new characteristics not

deter-mined by the original fertilized egg may

emerge in the process of embryonic

develop-ment, such as a pregnant woman listening to

classical music in order to influence her new

child’s intellectual level; cf.,

homunculus/sen-sory homunculus hypothesis - a “homunculus”

is a completely formed “minute/miniature

human figure” considered by some 16th- and

17th-century theorists to exist in the

spermato-zoon and to expand in size in the transitions

from zygote to embryo to infant to adult; this

notion is an example of preformism and

op-poses the epigenetic principle of cumulative

development and successive differentiation;

the homunculus hypothesis was advanced,

al-so, by the early Egyptians who held that a

little person resides inside each person’s skull

and where the homunculus - after looking out

through the person’s eyes and listening via the

person’s ears - reacts to the environment by

pulling strings to operate the person’s

mus-cles; in the sensory homunculus hypothesis, it

is suggested that the behavior of an organism

is controlled and regulated by a cognitive agent called the “homunculus” that is located within the individual’s brain and whose be-havior is just as complex as is the individual’s behavior that is being explained; in more re-

cent times, the homunculus is portrayed as a

“tiny, grotesque-looking man” whose distorted body parts indicate the relative sizes of their sensory projection areas in the somatosensory cortex; for example, the head, the hands –

especially the thumbs, and feet of the culus are grossly exaggerated in size to signify

homun-their relative importance and representations

in the somatosensory cortical regions) In

Weismann’s view, germ plasms give the tinuity from parent to offspring; all other cells

con-are merely a vehicle to convey the germ plasm, and it alone is, in a sense, immortal; other cells are destined to die Weismann also notes that some form of reduction division - that is now known to occur during meiosis -

must occur if the genetic material is not to double on each generation (cf., central dogma principle - the proposition that states that ge-

netic information is transferred from DNA to the proteins that it encodes, and not from pro-tein to DNA; that is, although genes can influ-ence the form of an organism’s body or its behavior, the form of the organism’s body or its behavior cannot influence its genes; and

genetic memory/storage theory - posits that

information from learning or experience may

be stored in a DNA or RNA molecule which,

in turn, may be inherited as part of a some) Weismann’s ideas are only broadly correct, but it is surprising that he was able in the 1880s to get so near the modern view He was wrong in his belief that the germ plasm is unalterable and immune to environmental effects, as others were to demonstrate later Weismann’s theories appeared originally in a series of essays, translated as “Essays Upon Heredity and Kindred Biological Problems” (1889-1892), and his “Vortrage Uber Descen-denztheorie” (1902) was an important contri-

chromo-bution to evolutionary theory See also

DAR-WIN’S EVOLUTION THEORY; TON’S LAWS; HARDY-WEINBERG LAW; LAMARCK’S THEORY; MENDEL’S LAWS/PRINCIPLES

Millar, D., Millar, I., Millar, J., & Millar, M

(1996) The Cambridge dictionary

of scientists New York: Cambridge

University Press

WELLS EFFECT The American

psycholo-gist Gary Leroy Wells (1950- ) suggests in

the Wells effect that individuals have a

reluc-tance to make judgments of legal liability

solely on the basis of “naked” statistical

evi-dence For example, evidence that is highly

reliable (say 80-percent) is sufficient to

per-suade most people, or to influence their

deci-sions, but “naked” statistical evidence (e.g.,

evidence having an 80-percent probability) is

not sufficient to persuade most people - even

though the actual mathematical probability is

the same in both instances (i.e., reliable

evi-dence versus statistical evievi-dence) See also

DECISION-MAKING THEORIES;

EX-PECTED UTILITY THEORY; TAXICAB

PROBLEM/EFFECT

REFERENCES

Wells, G L (1978) Applied eyewitness

tes-timony research: system variables

and estimator variables Journal of

Personality and Social Psychology,

36, 1546-1557

Wells, G L (1984) How adequate is human

intuition for judging eyewitness

tes-timony? In G L Wells & E F

Loftus (Eds.), Eyewitness testimony:

Psychological perspectives New

York: Cambridge University Press

Wells, G L (1993) What do we know about

eyewitness identification? American

Psychologist, 48, 553-571

Wells, G L., & Olson, E A (2003)

Eye-witness testimony Annual Review of

Psychology, 54, 277-295

WERNICKE-GESCHWIND THEORY

See MIND/MENTAL STATES, THEORIES

OF

WERTHEIMER’S PERCEPTUAL

THE-ORY See GESTALT THEORY/LAWS

WEVER-BRAY EFFECT See AUDITION/

HEARING, THEORIES OF

WHEATSTONE-PANUM LIMITING CASE See PANUM PHENOMENON/EF-

FECT

WHITTEN EFFECT See OLFACTION/

SMELL, THEORIES OF

WHORF-SAPIR

HYPOTHESIS/THEO-RY = Whorfian hypothesis = Whorf’s

hy-pothesis = linguistic relativity hyhy-pothesis = Sapir-Whorf hypothesis The American lin-guists and anthropologists Benjamin Lee Whorf (1897-1941) and Edward Sapir (1884-

1939) formulated the Whorf-Sapir linguistic hypothesis, which states that one’s language influences the nature of one’s perceptions and thoughts, and was first suggested by the Ger-

man ethnologist Wilhelm von Humboldt

(1767-1835) There are two forms of the guistic relativity hypothesis: a “weak” form

lin-(which argues that only perceptions are so influenced; e.g., an Eskimo’s perception of

snow is distinguishable from a non-Eskimo’s

because the former has many different words

in his/her vocabulary/language for different

variations in types of snow), and a “strong”

form (which asserts that abstract conceptual processes are so affected; e.g., the Hopi Indian

language handles time in a relativistic manner

as compared with the English language

break-down of time into “past,” “present,” and

“fu-ture”) Unfortunately, very little convincing

evidence supports completely the Whorf-Sapir hypothesis An early view of the relationship between language and thought was J B Wat- son’s (1878-1958) behaviorist approach that

asserted that one learns to talk in much the same way that other muscular skills (such as riding a bicycle) are learned, and when one subsequently makes the same muscular movements in a more hidden form (i.e., to oneself covertly rather than aloud or overtly),

it is called thought [cf., the motor theory of thinking/consciousness of E Jacobson (1932)

and L W Max (1935), which posits that tal images are accompanied by changes in the corresponding muscular area - such as the arm and eye regions of the body - for motor and

men-visual images, respectively; Flourens’ theory -

named after the French physician Marie-Pierre

Jean Flourens (1794-1867), states that

think-ing depends on the functionthink-ing of the

cere-brum as a whole; the laws of thought - refer to

the three logical principles of identity,

contra-diction, and excluded middle, and are

consid-ered to be the basic principles of all reasoning;

and the law of participation - is a principle of

human primitive thinking, which asserts that

things that are similar are considered to be

identical] According to Watson, what

psy-chologists call thought is nothing but talking

to oneself (cf., the motor theory of speech

perception propounded by A M Liberman,

which holds that speech is assumed to be

per-ceived by an implicit, covert system that

“maps” the acoustic properties of the input

against a set of deep motor representations of

idealized articulation) However, Watson’s

extreme behaviorist view that thinking or

thought depends only on the implicit muscle

movements of speech has proven to be

inade-quate [cf., central theory of thinking - is the

proposition that the center of mentation is a

cerebral process located in the brain

(how-ever, curiously, Aristotle suggested that the

locus of thinking/thought is in the heart)]

Kinney’s law - named after the American

edu-cator Richard Kinney (1924-1979), relates to

temporal factors and behavioral/quantitative

aspects of speech deficiency in postnatally

developing deafness where the length of time

over which changes in speech develop is

di-rectly proportional to the length of time during

which normal speech has been present; and

the phonemic restoration phantom/effect -

refers to the generalization that a dramatically

altered acoustic element in speech is

ex-tremely difficult to detect, and where

replac-ing various speech sounds with others still

sounds like proper speech Other competing

theories concerning the relationship between

language and thought are: J Piaget’s cognitive

stage development theory, which emphasizes

the idea that language is a result/by-product of

a child’s advances in cognitive abilities,

par-ticularly the ability to symbolize that develops

at the end of infancy; and the Russian

devel-opmental psychologist Lev S Vygotsky’s

(1896-1934) and the Russian

neuropsycholo-gist Aleksandr R Luria’s (1902-1977)

linguis-tic theory that portrays language and thought

as developing together and aiding each other

in the process (cf., concept of pure meaning -

Vygotsky’s notion maintaining that “pure

meaning” is the final union of language and thought in adult reasoning; language and thought begin as independent processes, but

join together around the age of two years, and lead to the development of egocentric speech, inner speech, verbal thought, concept forma-tion and, ultimately, “pure meaning”) It is

suggested that the notion of linguistic ity (like most “large” theories in psychology)

relativ-is not the kind of theory that will ever be proven completely right or completely wrong; most likely, in the final analysis, it may be

proper to say that language differences ence people’s thoughts and perceptions in some ways, as well as, conversely, thoughts/ cognitions and perceptions influence one’s language in other ways (cf., cloak theory of language - holds that the structure of a lan-

influ-guage is a dependent function of the patterns

of thought embedded in the particular culture) See also BEHAVIORIST THEORY; CHOM-SKY’S PSYCHOLINGUISTIC THEORY; CONCEPT LEARNING/CONCEPT FOR-MATION, THEORIES OF; LANGUAGE ACQUISITION THEORY; LANGUAGE ORIGINS, THEORIES OF; PIAGET’S DE-VELOPMENTAL STAGES THEORY; SPEECH THEORIES; THOUGHT, LAWS

OF

REFERENCES

Watson, J B (1924) Behaviorism Chicago:

University of Chicago Press

Vygotsky, L S., & Luria, A R (1930)

Stud-ies in the history of behaviour

Cambridge, MA: M.I.T Press

Jacobson, E (1932) Electrophysiology of

mental activities American Journal

of Psychology, 44, 677-694

Vygotsky, L S (1934/1962) Thought and

language Cambridge, MA: M.I.T

Press

Max, L W (1935) An experimental study of

the motor theory of consciousness

Journal of Comparative Psychology,

19, 469-486

Piaget, J (1954) The construction of reality in

the child New York: Basic Books Whorf, B (1956) Language, thought, and

reality New York: Wiley

Luria, A R (1968) The mind of a mnemonist

New York: Basic Books

Kay, P., & Kempton, W (1984) What is the

Sapir-Whorf hypothesis? American

Anthropologist, 86, 65-79

Hunt, E., & Agnoli, F (1991) The Whorfian

hypothesis: A cognitive psychology

perspective Psychological Review,

98, 377-389

WIFE/MISTRESS FIGURE See

APPEN-DIX A, RUBIN FIGURE/ILLUSION

WILD CHILD PHENOMENON See

KAS-PAR HAUSER EFFECT/EXPERIMENT

WILDER’S LAW OF INITIAL VALUE(S)

See INITIAL VALUE(S), LAW OF

WILLMER’S COLOR THEORY.The

British physiologist E N Willmer (dates

un-known) proposed a theory of color vision that

postulates three mechanisms in the retina:

cones, dark-adapting rods, and

non-dark-adapting rods Willmer’s color theory asserts

that color vision may be explained by the

rela-tive ratio of rods and cones at various

wave-lengths, and indicates that when a curve is

plotted to show the summation of rod and

cone responses at various wavelengths of the

visible spectrum, the curve has some affinity

to the well-known color triangle Thus,

Will-mer’s color theory was developed via analyses

of sensitivity to wavelengths and relates to

empirically-derived hue/color charts; the

the-ory also attempts to account for the

relation-ship of hue to intensity and with the

white-black phenomena in color vision Willmer

(1943) presents his theory, examines the

physiology of color vision, and discusses the

deficiencies in color-vision theory in the

jour-nal Nature (London) and, in the same issue of

the journal - in response to his article, K J W

Craik, H Hartridge, and A H S Holbourn

raise several objections to Willmer’s theory

Craik describes an experiment that

demon-strates that a hue match with yellow or green

is impossible when red and blue are used

within the photopic/scotopic ratios covering

the regions stated in Willmer’s theory, and

Craik also criticizes the theory concerning the

production of the “white sensation.” Hartridge

describes an experiment that fails to

corrobo-rate certain assumptions of Willmer’s theory,

namely, that strong stimulation of the rods and cones simultaneously would cause an appre-ciation of green, yellow, or orange, whereas weak stimulation of those receptors should result in the perception of violet, mauve, or

crimson Holbourn offers a criticism of mer’s theory by pointing out that any worka- ble color theory must have three independent variables, but Willmer’s theory only has two

Will-independent variables.See also COLOR SION, THEORIES/LAWS OF

VI-REFERENCES

Willmer, E N (1943) Physiology of colour

vision Nature (London), 151-152,

191, 213-215, 632-635

Willmer, E N (1946) Retinal structure and

colour vision: A restatement and an hypothesis Cambridge, UK: Cam-

bridge University Press

Willmer, E N (1950) Some aspects of

col-our-blindness British Medical nal, 2, 1141-1145

Jour-Giles, G H (1950) Colour vision: Some

re-cent trends in practice British nal of Physiological Optics, 7, 90-

Jour-95

Willmer, E N (1955) The physiology of

vision Annual Review of ogy, 17, 339-366.

Physiol-WINNER’S CURSE EFFECT See

DE-CISION-MAKING THEORIES

WITKIN’S ITY/COGNITIVE STYLE THEORY The

PERCEPTION/PERSONAL-American psychologist Herman A Witkin

(1916-1979) conducted research on cognitive styles in the 1940s, in particular on individual

differences in the perception of the upright in space An earlier approach toward understand-ing visual space perception, especially one related to the perception of rotation/movement

in space, was provided by the Austrian cist/philosopher Ernst Mach (1838-1916) in

physi-his theory of bodily rotation (also called the Mach-Breuer-Brown theory of labyrinthine functioning), where he suggested that the

sense organs for this experience are to be found in the semicircular canals of the inner

ear Mach’s theory, with some modification, is

still prevalent today In Witkin’s theoretical

approach, when stationary visual and bodily

cues are placed in opposition, and one has to

judge whether an object is upright, some

per-sons are influenced more by the visual cues

(such individuals are called field-dependent),

whereas others depend more on bodily cues

(these persons are called field-independent)

The factors of field dependence and field

in-dependence represent a dimension along

which one’s perceptions may be placed

con-cerning dependence on (or independence

from) cues in the environment (called the

field) In the first and simplest test (called the

rod and frame test or RFT) used to study this

dimension, a participant has to align a

stimu-lus (such as a rod) so that it is “truly” vertical

when a second stimulus (such as a frame

around the rod) is varied with respect to the

true vertical Persons who can set the rod

rela-tively accurately - independently of the

orien-tation of the frame - are called

field-independent because they rely on bodily

sen-sation cues rather than on visual cues in the

field The more the tilt in the field controls the

person’s setting of the rod, the more

field-dependent the individual Another test of the

field independent-dependent dimension is the

embedded-figures test [described by the

Ger-man Gestalt psychologist Kurt Gottschaldt

(1902-1991) in 1926] in which the participant

attempts to locate simple geometric shapes

that are hidden in more complex diagrams/

drawings; field-independent persons perform

better on this test than do field-dependent

per-sons Later, Witkin and others conducted more

elaborate studies using chairs and entire rooms

that could be tilted (in the tilting-room test or

body-adjustment test) The study of the trait

field dependence began in the area of

percep-tion, but the large individual differences that

were found in tests such as RFT,

embedded-figures, and the tilting-room encouraged

re-search in other areas such as personality,

emo-tions, cognitive style, neuropsychological

processes, development, and

psychopathol-ogy Witkin argued that individuals move, in

general, from field-dependence toward field-

independence as they mature However, those

who become most field-independent are those

individuals who are raised in ways that foster

personal autonomy and a secure sense of self

Witkin’s research led to a variety of studies including dreaming, cultural differences in socialization, intellectual processes, interper-sonal relations (e.g., between teachers and students, therapists and patients/clients, and parents and children), brain laterality, and chromosomal aberrations See also BERKE-LEY’S THEORY OF VISUAL SPACE PER-CEPTION; COGNITIVE STYLE MODELS; GESTALT THEORY/LAWS; LATERALITY THEORIES; PERCEPTION (II COMPARA-TIVE APPRAISAL), THEORIES OF; PER-SONALITY, THEORIES OF; SELF-CONCEPT THEORY

REFERENCES

Mach, E (1886/1959) The analysis of

sensa-tions and the relation of the physical

to the psychical New York: Dover Mach, E (1902) The analysis of experience

Jena, East Germany: Fisher

Witkin, H A (1950) Individual differences in

ease of perception of embedded

fig-ures Journal of Personality, 19,

1-15

Witkin, H A., & Goodenough, D (1977)

Field dependence and interpersonal

behavior Psychological Bulletin,

84, 661-689

Witkin, H A., & Goodenough, D (1981)

Cognitive styles: Essence and gins - Field dependence and filed independence New York: Interna-

ori-tional Universities Press

WIT, THEORIES OF See HUMOR,

THE-ORIES OF

WOLPE’S THEORY/TECHNIQUE OF RECIPROCAL INHIBITION The South

African-born American psychiatrist Joseph Wolpe (1915-1997) conducted experimental studies early in his career on the production and cure of neuroses in animals which demon-strated that the neuroses could be produced in learning and, also, could be reversible by learning Later, based on such research, Wolpe derived psychotherapeutic techniques for

treating neuroses in humans Wolpe’s theory and technique constituted one of the many varieties of behavior modification (or behav- ior therapy, which is a procedure of direct

intervention to alter a person’s behaviors to

situations that are deemed - by oneself or by

others - to be worthy of change; cf., Ahsen,

1989) Wolpe’s approach, called reciprocal

inhibition, is a form of behavior therapy that

is based on the neurological concept of

recip-rocal innervation, that is, the inhibition of the

action of one neural pathway by the activity of

another (cf., staircase phenomenon or

warm-up effect - refers to a graduated sequence of

increasingly stronger muscle contractions that

occur when a corresponding sequence of

iden-tical stimuli is applied to a rested muscle; cf.,

Bowditch’s law) As a general theory of

be-havior modification, Wolpe’s reciprocal

inhi-bition refers to the inhiinhi-bition of one response

(e.g., yelling) by the occurrence of another

mutually incompatible response (e.g., talking

softly) The specific method used in

recipro-cal inhibition is recipro-called desensitization or

sys-tematic desensitization [cf., progressive

re-laxation - a form of psychotherapy used for

treating anxiety disorders whereby skeletal

muscles throughout the body are first tensed

and then relaxed deeply; it was first described

in 1929 by the American physician Edmund

Jacobson (1888-1983) and is used, often, as an

adjunct to systematic desensitization] In a

clinical context, especially in the treatment of

phobias (“irrational fears”), the procedure of

systematic desensitization is designed to

pro-duce a decrease in anxiety (i.e., “de-sensitize”)

toward some feared situation of object (e.g.,

snakes) This is accomplished by exposing the

client to a series of approximations to the

anxiety-producing stimulus under relaxed

conditions until, eventually, the anxiety

reac-tion becomes extinguished The procedure of

systematic desensitization has come under

heavy criticism from psychoanalytically

ori-ented therapists and theorists over the issue of

the symptom substitution hypothesis (i.e., the

idea that if only the surface or superficial

be-havioral manifestations of a neurosis are

treat-ed in psychotherapy, the presumtreat-ed unresolvtreat-ed

underlying conflict will “erupt” elsewhere,

and new symptoms will emerge) The notion

of symptom substitution derives from the

as-sumption (not accepted by all psychologists)

that psychological disturbances are analogous

to medical disturbances (as in the medical/

disease model of illness) in that they can be

treated only by removal of the root cause of

the disorder (cf., resolution law - attempts to

find a partial explanation of behavioral fication whereby the changing of one physio-logical state into another one becomes easier and quicker after it has taken place a number

modi-of times; and stages modi-of change theory –

sug-gests the following steps be used to gain the self-control required to change an undesirable behavior: pre-contemplation of the advantages and consequences of the change, contempla-tion of benefits, preparation and action, and maintenance of the change) Wolpe indicates that variables such as food, expression of ag-gression, and sexual feeling might work, also,

to reciprocally inhibit avoidance behavior or anxiety feelings Wolpe’s work on the direct

re-education of sexual behavior foreshadowed

W Masters and V Johnson’s widely cized sexual-response studies, and his empha-sis on expression of feeling anticipated the

publi-procedure of assertiveness training See also

ALL-OR-NONE LAW/PRINCIPLE; VIOR THERAPY/COGNITIVE THERAPY, THEORIES OF; BOWDITCH’S LAW; IM-AGERY/MENTAL IMAGERY, THEORIES

BEHA-OF

REFERENCES

Jacobson, E (1929) Progressive relaxation

Chicago: University of Chicago Press

Wolpe, J (1952) Experimental neurosis as

learned behavior British Journal of Psychology, 43, 243-268

Wolpe, J (1954) Reciprocal inhibition as the

main basis of psychotherapeutic

ef-fects Archives of Neurological chiatry, 72, 205-226

Psy-Wolpe, J (1958) Psychotherapy by

recipro-cal inhibition Stanford, CA:

Stan-ford University Press

Masters, W., & Johnson, V (1966) Human

sexual response Boston: Little,

Brown

Ahsen, A (1989) Scientific misconduct in

behaviorist circles Journal of tal Imagery, 13, 1-20

Men-WORD-LENGTH EFFECT See

FORGET-TING/MEMORY, THEORIES OF

WORD-SUPERIORITY EFFECT See

TOP-DOWN PROCESSING/THEORIES

WORK ADJUSTMENT, THEORY OF

See WORK/CAREER/OCCUPATION,

THE-ORIES OF

WORK/CAREER/OCCUPATION,

THE-ORIES OF.The psychological study of work,

career, and occupational factors ranges from

theories of decision-making in career

devel-opment to

ergonomic/ergopsychometry/anth-ropometry, human engineering/human factors,

work fatigue/efficiency, applications research,

and work motivation theories Theories of

career development fall into one of several

classes: trait-oriented, systems-oriented,

per-sonality-oriented, or developmental Although

no single approach seems to dominate the

field, each has its own particular utility for

career/work/occupation counselors Once a

person makes a career decision, potential

problems exist in terms of worker

productiv-ity, adjustment to the stress/strain of the

workplace, and level of job satisfaction

Theo-ries in vocational psychology may be divided

into four main categories: matching

ap-proaches (involves theories and methods

based on studies in the area of differential

psychology and on situational theories);

phe-nomenological approaches (involves

self-concept theory and congruence theory; cf.,

consistency theory of work behavior - holds

that work behavior is based on two allied

premises: a balance concept and a self-image

standard; the theory predicts that workers will

engage in satisfying behaviors that maximize

their sense of cognitive balance and will be

motivated to perform in a way that is

consis-tent with their self-image); developmental

approaches (includes role theory and life-stage

theory), and decision-making approaches

Theories of work/job efficiency attempt to

account for effective work performance and

how stress, strain, boredom, fatigue, and other

negative consequences of work affect one’s

health and well-being The theories of work

motivation may be grouped into two broad

areas: universalistic theories - posit

wide-spread applicability to the work environment,

and contingency theories - focus on individual

differences that influence motivation levels

Among the universalistic theories are A

Maslow’s hierarchy of needs theory -

pro-poses that human behavior is a result of

at-tempts to satisfy currently unsatisfied needs where the needs are arranged in a hierarchical order such that the satisfaction of a prior level

of need leads to a need for satisfaction at a

succeeding level [cf., existence, relatedness, and growth theory, or ERG theory, is a varia- tion of Mas-low’s hierarchy of needs theory as

applied to occupational/industrial settings,

where need categories include existence needs

(relative to the person’s physical needs such as

food, clothing, and shelter), relatedness needs

(relating to interpersonal relations with others,

both on and off the job), and growth needs]; F Herzberg’s two-factor theory - asserts that job

satisfaction and dissatisfaction are caused by different work-related factors such as achievement, recognition, advancement,

growth, and responsibility as satisfiers, and

lack of company policy, administration, nical support/ supervision, salary, job security,

tech-fringe benefits, and status as dissatisfiers; and

D McClelland’s achievement motivation ory - focuses on the needs of power, affilia-

the-tion, and achievement as prominent

work-related factors Among the contingency ries are B F Skinner’s stimulus-response and operant conditioning theory - argues that hu- man behavior is not motivated by needs within

theo-an individual but by the external environment

and the rewards and punishments that it

pro-vides; J S Adams’ equity theory - assumes

that persons are motivated by a desire to be treated equitably on their jobs; and V H

Vroom’s force model in occupational choice and expectancy theory (also called valence- expectancy theory and valence- instrumentality-expectancy theory) - asserts

that a person’s motivation to perform is a function of both perceived desirability and attainability of outcomes, and suggests the behavior is affected by degree of cer-tainty/uncertainty that some outcome will follow the behavior, and how much that out-

come is valued by the worker (cf., tality theory - a cognitive approach to work

instrumen-motivation that states that a person’s attitude about an event/work depends on the percep-tion of the event’s/work’s function as an in-strument in obtaining the desirable, or unde-

sirable, consequences; and role-expectations hypothesis - posits that confirmation of em-

ployees’ prior expectations about the nature of

their jobs results in lower job turn-over and

higher degrees of organizational commitment

and job satisfaction) Closely related to work

motivation is the issue of occupational

ad-justment, which is also a major source of

per-sonal identity and role definition One

well-formulated theory of work adjustment (cf.,

Lofquist & Dawis, 1969) maintains that

occu-pational environments provide different

pat-terns of reinforcement that interact with a

person’s needs and abilities, and where

har-mony between an individual and the work

environment results in satisfaction and, as a

consequence, greater level of work stability

(cf., job-characteristics model - holds that

particular needs of employees, such as

auton-omy, feedback, identity, significance, and task

variety, influence job adjustment, satisfaction,

and other employee outcomes; range-of-affect

hypothesis - in the prediction of job

satisfac-tion, this conjecture attempts to explain how

the discrepancies between what one already

has, and what one wants, determine the

poten-tial range of satisfaction yielded by a given

job aspect/facet; and vitamin model of

em-ployee satisfaction - states that different

as-pects of work, much like taking daily dosages

of vitamins, need to be present, at least

mini-mally, in order to produce a satisfied

em-ployee) The theories of motivation and

ad-justment have practical implications for

work-related activities in organizations and

contrib-ute to the maximization of job satisfaction and

worker morale See also BALANCE,

PRIN-CIPLES/THEORY OF;

DECISION-MAK-ING THEORIES; DEVELOPMENTAL

THE-ORY; LEADERSHIP, THEORIES OF;

MAS-LOW’S THEORY OF PERSONALITY;

MO-TIVATION, THEORIES OF;

ORGANIZA-TIONAL/INDUSTRIAL/SYSTEMS THEO-

RY; PERSONALITY THEORIES;

ROLE-THEORY OF PERSONALITY;

SELF-CON-CEPT THEORY; SITUATIONAL THEORY

OF LEADERSHIP

REFERENCES

Taylor, F (1903) Shop management New

York: Harper

Gilbreth, F (1911) Motion study, a method

for increasing efficiency New York:

Van Nostrand

Maslow, A (1943) A theory of human

moti-vation Psychological Review, 50,

370-396

McClelland, D., Atkinson, J., Clark, R., &

Lowell, E (1953) The achievement motive New York: A-C-C

Herzberg, F., Mausner, B., & Snyderman, B

(1959) The motivation to work

New York: Wiley

Adams, J S (1963) Toward an understanding

of inequity Journal of Abnormal and Social Psychology, 67, 422-436 Vroom, V H (1964) Work and motivation

New York: Wiley

Osipow, S (1968/1983) Theories of career

development Englewood Cliffs, NJ:

Prentice-Hall

Lofquist, L., & Dawis, R (1969) Adjustment

to work New York: A-C-C

Skinner, B F (1971) Beyond freedom and

dignity New York: Bantam Books

Super, D (1994) Career development In R J

Corsini (Ed.), Encyclopedia of chology New York: Wiley

psy-Latham, G P., & Pinder, C C (2005) Work

motivation theory and research at the dawn of the twenty-first century

Annual Review of Psychology, 56,

485-516

WORKING MEMORY, THEORY OF In

memory/learning psychology, as advanced by the English psychologists Alan D Baddeley (1934- ) and Graham J Hitch (1946- ), the

theory of working memory refers to the

tempo-rary storage system that retains received information items while an interpre-tation process is activated to sort out this in-

currently-put This working memory system allows for

manipulation of the information and its

pas-sage in, and out of, short-term memory

Theo-retically, regarding verbal materials, such as sentences, the words in a sentence are held in their literal and original form or state while a more abstract process works to shape and determine the meaning of the sentence More-over, the storage system is thought to involve

a “central executive” component (language comprehension processor) and two “buffer” components (temporary memory storage also known as “blackboard memory” components)

called the phonological loop model (an

inner-speech, verbal, or mental rehearsal

tactic-device, lasting up to two seconds) and the

visuospatial sketchpad/scratch-pad model (a

visual-coding mechanism, assumed to be

re-sponsible for establishing and manipulating

visuo-spatial images) Concerning its location,

it is speculated that the associative processes

of working memory are carried out mostly in

the brain’s prefrontal cortex Working memory

has been studied by psychologists in diverse

human and non-human organisms via

tech-niques such as “object permanence” and

“de-layed-reaction” tests See also CHOMSKY’S

PSYCHOLINGUISTIC THEORY;

DE-LAYED-REACTION PARADIGM; OBJECT

PERMANENCE PARADIGM;

SHORT-TERM AND LONG-SHORT-TERM MEMORY,

THEORIES OF

REFERENCE

Baddeley, A D., & Hitch, G J (1974)

Work-ing memory In G Bower (Ed.),

Re-cent advances in learning and

moti-vation Vol 8 New York:

Aca-demic Press

WUNDT ILLUSION See APPENDIX A

WUNDT’S THEORIES/DOCTRINES/

PRINCIPLES The German physiologist,

psychologist, philosopher, and founder of

experimental psychology Wilhelm Max

Wundt (1832-1920) created and developed the

first school of psychological thought, called

structuralism/structuralist school, whose basic

ten-et was that sensations are the proper

sub-ject matter of psychology (the historical

psy-chological school/theory of functionalism

emphasized the activity/adaptive dimension of

psychological events, whereas Wundt’s

the-ory/ school of structuralism emphasized the

contents of psychological events) Using the

method of introspection (i.e., looking within

one’s own experience and reporting on it),

Wundt and his students investigated

partici-pants’ immediate experience through exacting

attention to sensations and feelings The goals

of structuralism were to analyze conscious

processes into basic elements, to determine

how these elements are connected, and to

establish the laws of these connections (cf.,

Ahsen, 1986) Wundt proposed a

tridimen-sional theory of feeling in which an

equilib-rium between pleasure-displeasure, relaxation, and excitement-calm/depression occupy three independent and distinct dimen-sions of feeling Wundt held that emotions are complex compounds of the elementary feel-ings and that each of the feelings may effec-tively be described by defining its position on each of the three dimensions (cf., Wundt’s

tension-formulation of three principles of emotional expression as a reformulation of Darwin’s principles: the principles of innervation, asso- ciation of analogous sensations, and relation

of movements to images) Wundt’s theory of feeling stimulated a great deal of research in

his own, and rival, laboratories but it has not withstood the test of time Wundt postulated

his doctrine of apperception to explain how

the various elements of conscious experience are combined to form unified conscious ex-

periences He used the term apperception in a

fashion similar to that of the German pher/psychologist Johann Herbart (1776-1841)

philoso-to refer philoso-to the active mental process of ing and structuring internal experience The

select-term apperception is rarely used today in

ex-perimental psychology, but the concepts derlying it are important, especially to many cognitively oriented psychologists Wundt designated the active process of combining the

un-various elements into a unity as his law of psychic resultants (also called the principle of creative synthesis/resultants), which states

that the combination of elements creates new properties where every psychic compound has characteristics that are more than the sum of the characteristics of the elements when taken singly (cf., Mill, 1874) In a sense, Wundt’s

principle of creative synthesis (via J S Mill) and his law of psychic resultants anticipated

the Gestalt theorists’ viewpoint that in tion the “whole is more than the sum of its parts,” where something new is created out of the synthesis of the elemental parts of experi-

percep-ence [cf., synergy theory - developed by the

American functionalist/dynamic psychologist Robert Sessions Woodworth (1869-1962), and emphasizes the idea that mental synthesis is a unitary perceptual or motor response that is generated by the aggregate of sensory ele-ments, and is viewed as stimuli converging on

a single response mechanism; and dynamic

theory - a general approach employed by both

Sigmund Freud and Wilhelm Wundt that is

concerned with motivational processes and the

unconscious; the term dynamism is used to

refer to a stable manner of behaving, the

pur-pose of which is to fulfill motives and drives

and to protect the individual from debilitating

stress] At the turn of the 20th century, Wundt

was involved in an academic controversy

call-ed the imageless thought debate The

contro-versy about the nature of thinking was

be-tween the structuralist school of Wundt and E

B Titchener on the one hand, and the

mem-bers of the Wurzburg school in Germany on

the other hand Wundt postulated that

con-sciousness is made up of only three elements:

sensations, images, and feelings; Titchener

placed major emphasis on images as the

vehi-cles of thought The Wurzburg psychologists

hypothesized that participants’ responses are

due to determining tendencies or sets without

the use of imagery (i.e., they argued in favor

of “imageless thought”) The topic of images/

imagery waned with the advent of

behavior-ism in the early 1900s, but then in the 1960s

and 1970s, it was revived with the

develop-ment of the cognitive approach in psychology,

and imagery began to play a significant

theo-retical role in the areas of learning, perception,

thinking, and meaning Wundt’s wide-ranging

laboratory investigations of psychological

phenomena included the psychology and

physiology of seeing, hearing, the “lower”

senses, optics, reaction-time experiments,

word associations, folk psychology, and

psy-chophysics Wundt adopted a purely

psycho-logical interpretation of Weber’s law, which

he considered to be an example of the

psycho-logical law of relativity (cf., Muller, 1878)

Although there were signs reflecting the

theo-retical narrowness of Wundt’s new

experi-mental psychology, it was through Wundt’s

vision, largely, that the conception of an

inde-pendent and inductive psychology became a

reality See also ACH’S

LAWS/PRINCIPLES/THEORY;

BEHAV-IORIST THEORY; DARWIN’S

EV-OLUTION THEORY; DARWIN’S THEORY

OF EMOTIONS; DETERMINING

TEN-DENCY; DONDERS’ LAW; DYNAMIC

THEORY; FUNCTIONALISM THEORY;

GESTALT THEORY/LAWS; HERBART’S

DOCTRINE OF APPERCEPTION; AGERY/MENTAL IMAGERY, THEORIES OF; MILL’S CANONS; MOTIVATION, THEORIES OF; SET, LAW OF; WEBER’S LAW

IM-REFERENCES

Wundt, W M (1862) Beitrage zur theorie

der sinneswahrnehmung Leipzig:

Engelmann

Wundt, W M (1873) Grundzuege der

physi-ologischen psychologie Leipzig:

Engelmann

Mill, J S (1874) A system of logic New

York: Harper

Muller, G (1878) Zur grundlegung der

psy-chophysik Berlin: Gruben

Wundt, W M (1896) Grundriss der

psycho-logie Leipzig: Engelmann

Wundt, W M (1897) Principles of

psycholo-gy Leipzig: Engelmann

Ahsen, A (1986) The New Structuralism:

Images in dramatic interlock nal of Mental Imagery, 10, 1-92

Jour-WYER AND COLLINS’ THEORY OF HUMOR ELICITATION This theory of

humor (that borrows heavily from several

aspects of M J Apter’s reversal theory)

specifies the conditions in which humor is experienced both in social and non-social

situations The theory of humor elicitation

(Wyer & Collins, 1992) emphasizes the lowing aspects: the interpretation of a stimu-lus-event that is necessary to evoke humor; the problems of identifying the humor-eliciting characteristics of the stimulus-event interpre-tation; and the cognitive elaboration of the various implications of the stimulus-event

fol-Moreover, the theory of humor elicitation

assesses the persons’ information-processing objectives at the time a stimulus-event occurs; and, in particular, the theory has been used to conceptualize the humor evoked by witti-cisms, jokes, and social events that are neither intended nor expected to be humorous In their

comprehension-elaboration theory of humor,

Wyer and Collins propose a series of eight postulates (memory, encoding, prior and later stimulus-events, incongruity resolution, prag-matic meaning, humor elicitation, comprehen-sion difficulty, cognitive elaboration) concern-ing the comprehension of semantic and epi-

sodic information, the conditions of humor elicitation, and the elaboration of stimulus-

events Thus, this theory of humor elicitation

is based on the assumption that situational and individual-differences variables that affect the perception of humor may be viewed in terms

of their mediating influence on certain information processes involving previously acquired concepts and general knowledge Overall, the theory focuses on the cognitive foundations of one’s responses to ethnic hu-mor and to humor that is directed toward one-self See also APTER’S REVERSAL THE-ORY OF HUMOR; HUMOR, THEORIES OF; MOTIVATIONAL THEORIES OF HU-MOR

social-REFERENCES

Apter, M J (1982) The experience of

motiva-tion: The theory of psychological reversals London: Academic Press

Wyer, R S., & Collins, J E (1992) A theory

of humor elicitation Psychological Review, 99, 663-688

X

X, THEORY See LEADERSHIP,

THEO-RIES OF;

ORGANIZATIONAL/INDUSTRI-AL/SYSTEMS THEORY

Y

YAVIS-HOUND PHENOMENA/

SYN-DROMES The American psychotherapist

William Schofield (1921- ) suggests that the

acronym YAVIS embodies the personal

quali-ties that therapists, counselors, and the

Ameri-can general public find most appealing in

pa-tients, clients, associates, and other

individu-als YAVIS refers to the attributes of young,

attractive, verbal, intelligent, and successful

On the other hand, the acronym HOUND

embodies personality characteristics that

therapists, counselors, and the American

gen-eral public find least appealing in patients,

clients, associates, and other individuals

HOUND refers to the qualities of humble, old,

unattractive, nonverbal, and dumb See also

PERSONALITY THEORIES

REFERENCE

Schofield, W (1964/1986) Psychotherapy:

The purchase of friendship

En-glewood Cliffs, NJ: Prentice-Hall/

New Brunswick, NJ: Transaction

YERKES-DODSON LAW This principle is

a statement of the relationship between

arousal level and quality of performance

for-mulated in 1908 by the American comparative

psychologists Robert Means Yerkes

(1876-1956) and John Dillingham Dodson (dates

unknown) The Yerkes-Dodson law, also

call-ed the invertcall-ed-U hypothesis, indicates that

there is an optimal level of arousal (e.g.,

moti-vation, anxiety) for tasks where moderate

levels of arousal facilitate problem solving,

but if stress or anxiety is too high (or too low),

the person does not process the important and

relevant cues (or ignores them), and optimal

learning and performance fail to occur Thus,

the Yerkes-Dodson law states that increased

drive will improve performance up to a point,

beyond which there is deterioration of

per-formance However, the law may need to be

qualified by various factors, one of which is

task “complexity.” That is, the complexity of

the task to be performed may need to be

ex-amined and controlled wherein the optimal level of motivation should be higher for a simple task than it is for a complex task For example, solving difficult mathematical prob-lems within a time limit (a complex task) may

be best accomplished by only a slight level of arousal instead of being highly aroused or excited On the other hand, sorting and re-shelving library books all day (a simple task) may best be done by creating a high level of motivation in the person On the whole, the

Yerkes-Dodson law seems reasonable and

useful, but it has received only mixed support from psychologists See also ACTIVATION/ AROUSAL THEORY; INVERTED-U HY-POTHESIS

REFERENCES

Yerkes, R M., & Dodson, J D (1908) The

relation of strength of stimulus to

rapidity of habit formation Journal

of Comparative Neurology and chology, 18, 459-482

Psy-Brown, W P (1965) The Yerkes-Dodson law

repealed Psychological Reports, 67,

663-666

Anderson, K., Revelle, W., & Lynch, M

(1989) Caffeine, impulsivity, and memory scanning: A comparison of two explanations for the Yerkes-

Dodson effect Motivation and tion, 13, 1-20

Emo-Anderson, K (1994) Impulsivity, caffeine,

and task difficulty: A

within-sub-jects test of the Yerkes-Dodson law Personality and Individual Differ- ences, 16, 813-819

Teigen, K (1994) Yerkes-Dodson: A law for

all seasons Theory & Psychology,

4, 525-547

YO-HE-HO THEORY See LANGUAGE

ORIGINS, THEORIES OF

YO-YO EFFECT See HUNGER,

three-ele-proposed that color vision is due to three

dif-ferent kinds of visual fibers Young’s original

theory was based on Sir Isaac Newton’s

(1642-1727) earlier demonstration in physics

of the existence of three primary colors (red,

green, and blue) Because Young found it

difficult to conceive of each sensitive point in

the retina as containing an infinite number of

particles to be capable of vibrating in perfect

unison with every possible undulation of light

energy, he suggested that there are only three

kinds of fibers corresponding to three primary

colors (red, green, and blue) Young expanded

his theory somewhat in 1807, but it remained

unrecognized, essentially, as it sat in the

Phi-losophical Transactions of the Royal Society

of London until 1852 when the German

physiologist/psychologist Hermann von

Helmholtz (1821-1894) rediscovered and

popularized it [the Scottish physicist James

Clerk Maxwell (1831-1879) is reputed, also,

to have “rediscovered” Young’s early work at

about the same time as did Helmholtz]

Helm-holtz wrote his quantitative line-element

treatment of color vision and color

discrimina-tion short-ly before his death [cf., Helmholtz’s

theory of accommodation - states that the

shape of the lens of the eye becomes convex

as the ciliary muscle relaxes, and flattens as

the ciliary muscle contracts; even though the

concept of the lens changing shape originated

with the French philosopher Rene Descartes

(1596-1650), it was Helmholtz who elaborated

the physiological mechanism involved in the

pro-cess] As he developed his quantitative

theory, Helmholtz studied whether or not hue

could be discriminated on the basis of

grada-tions in the intensity of three fundamental

processes (red, green, blue) that are evoked

whenever the retinal cones are stimulated by

light energy Today, this theory is known as

the Young-Helmholtz theory, and it postulates

three types of cones (red, green, blue), each

containing a different chemical substance

where each is sensitive maximally to a

differ-ent region of the electromagnetic spectrum

Consistent with the law of specific nerve

en-ergies, the red cones (if stimulated in

isola-tion) would give a “red” sensation, green

cones would give a “green” sensation, and

blue cones would give a “blue” sensation

Also, according to the theory, the rate of firing

(“excitability”) of each cone type depends on the wavelength of the stimulating light Thus, the phenomenal or subjective experience of

hue (i.e., “color”) depends on the relative

frequencies of impulses set up in the three

types of fibers, brightness (i.e., “intensity”)

depends on the total frequency of impulses in

all three fibers, and saturation (i.e., “purity”)

depends on the amount of white produced in any quantifiable fusion of the fibers All the other hues (including yellow, purple, and white or gray) are due to various combinations

of the three component activities The Helmholtz color vision theory contains widely

Young-accepted ideas by psychologists today and has

the advantages of accounting for the laws of color mixing and of parsimony over other

theories that advance the involvement of more than three receptor processes in the visual

experience However, the Young-Helmholtz theory does have a number of difficulties as-

sociated with it: accounting fully for the

ex-periences of color-blind individuals [cf., tonism, which is red-green color blindness,

Dal-and is named after the English chemist John Dalton (1766-1844) who had it and first de-

scribed it]; accounting for the brightness

func-tions of both normal and color-blind persons; and accounting for contrary evidence that

shows that the blue component in color vision

has different properties than either the red or green components See also ACCOMMODA-TION, LAW/PRINCIPLE OF; COLOR MIXTURE, LAWS/THEORY OF; COLOR VISION, THEORIES/LAWS OF; SPECIFIC NERVE ENERGIES, LAW OF

REFERENCES

Young, T (1801) On the mechanism of the

eye Philosophical Transactions of the Royal Society of London, 91, 23-

88

Young, T (1807) On the theory of light and

colours In W Savage (Ed.), tures in natural philosophy Vol 2

Lec-London: Joseph Johnson, St Paul’s Church Yard

Helmholtz, H von (1852) On the theory of

compound colours Philosophy gazine, 4, 519-534

Ma-Helmholtz, H von (1892) Versuch das

psy-chophysische gesetz auf die farben unterschiede trichromatischer augen

anzuwenden Zeitschrift fur chologie und Physiologie Sinnesor- gange, 3, 1-20

Psy-YOUNG’S COLOR VISION THEORY

See YOUNG-HELMHOLTZ COLOR ION THEORY

VIS-Y, THEORY See LEADERSHIP,

THEO-RIES OF

Z

ZAJONC’S AROUSAL AND

CONFLU-ENCE THEORIES The Polish-born social

psychologist Robert B Zajonc (1923- )

pro-posed the following generalization concerning

social facilitation (i.e., the tendency to

per-form a task better in the presence of others

than when alone) and social interference (i.e.,

a decline in performance when observers are

present): the presence of others facilitates

performance of dominant (i.e., simple,

habit-ual, or instinctive) responses and interferes

with performance of nondominant (i.e.,

com-plex, nonhabitual, or unnatural) responses (cf.,

audience effect or spectator effect - the

influ-ence of passive onlookers/spectators on a

person’s task performance; next-in-line effect -

refers to a decrement in recall for an event

immediately preceding an anticipated public

performance; and coaction effect - is the

influ-ence on a person’s task performance of the

presence of other people engaging in the same

activity) In the drive theory of social

facilita-tion, Zajonc explains both facilitation and

interference effects by linking them to the

more general phenomenon of the effect of

high arousal (drive) on performance That is,

high arousal typically improves performance

of simple or well-learned tasks and worsens

performance of complex or poorly-learned

tasks (cf., Yerkes & Dodson, 1908)

Accord-ing to Zajonc’s theory, the main effect of the

presence of others is to increase arousal after

which easy responses are easier, and difficult

responses become more difficult (cf.,

com-presence effect - is an arousal effect generated

by other people being present where,

depend-ing on conditions, performance is influenced

either positively or negatively) Studies of the

influence of others’ presence and the effects

of being observed on one’s performance go

back to the late 1800s (cf., Triplett, 1898) and

the early 1900s (cf., Allport, 1920), and report

social facilitation in some experiments but

social interference in other studies Zajonc’s

theory is able to explain both types of

out-come, suggesting that the mere presence of

others who are members of one’s own species

may enhance arousal innately Social tion has been observed in athletes, children,

facilita-chickens, and even cockroaches (that learn a maze faster if watched by other roaches)

Other theorists, however, explain such arousal

in somewhat different terms; for instance, in

terms such as evaluation anxiety (cf., Geen, 1991), self-perception of one’s skill at the task (cf., Sanna, 1992), and self-consciousness (cf.,

Baumeister & Showers, 1986) Zajonc’s

ex-planation for social facilitation is based in the context of a broader theory of emotion, in

which a person may have an emotional tion to a stimulus without any corresponding cognitive reaction; this theoretical approach

reac-differs from the two-factor theory of emotion

that posits a two-step self-perception process where one first experiences physiological arousal and seeks an explanation for it, and then it is the labeling of the arousal that is experienced as the emotion Zajonc has theo-rized, also concerning the influence of envi-ronmental factors on human intelligence, in particular the relationship between birth order

and intelligence (cf., birth order effect –

con-jecture that first-born children, and children, tend to be high achievers; also, the larger the family size, the lower the average

only-IQ of the children) In attempting to answer the finding of several studies that first-borns tend to have higher IQs than second-borns, who tend to have higher IQs than third-borns,

and so on, Zajonc’s confluence theory

sug-gests that each individual’s intellectual growth depends to an important degree on the intel-lectual environment in which the child devel-

ops Zajonc’s confluence theory and his

inter-pretation of the correlation between birth der and intelligence, however, are not univer-sally accepted, and have been the source of heated debate See also ACTIVATION/ AROUSAL THEORY; COGNITIVE THEO-RIES OF EMOTIONS; MERE EXPOSURE EFFECT; SCHACHTER-SINGER’S THE-ORY OF EMOTIONS; YERKES-DODSON LAW

or-REFERENCES

Triplett, N (1898) The dynamogenic factors

in peacemaking and competition

American Journal of Psychology, 9,

507-533

Yerkes, R M., & Dodson, J D (1908) The

relation of strength of stimulus to

rapidity of habit formation Journal

of Comparative Neurology and

Psy-chology, 18, 459-482

Allport, F (1920) The influence of group

upon association and thought

Jour-nal of Experimental Psychology, 3,

Quarter, J., & Marcus, A (1971) Drive level

and the audience effect: A test of

Zajonc’s theory Journal of Social

Psychology, 83, 99-105

Zajonc, R B., & Markus, G (1975) Birth

order and intellectual development

Psychological Review, 82, 74-88

Zajonc, R B (1976) Family configuration

and intelligence: Variations in

scho-lastic aptitude scores parallel trends

in family size and the spacing of

children Science, 192, 226-236

Zajonc, R B (1983) Validating the

conflu-ence model Psychological

Bull-etin, 93, 457-480

Zajonc, R B (1985) Emotion and facial

ef-ference: A theory reclaimed

Sci-ence, 228, 15-21

Baumeister, R., & Showers, C (1986) A

re-view of paradoxical performance

ef-fects: Choking under pressure in

sports and mental tests European

Journal of Social Psychology, 16,

361-383

Geen, R (1991) Social motivation Annual

Review of Psychology, 42, 377-399

Sanna, L (1992) Self-efficacy theory:

Impli-cations for social facilitation and

so-cial loafing Journal of Personality

and Social Psychology, 62, 774-786

ZANFORLIN ILLUSION See APPENDIX

A

ZEIGARNIK EFFECT/PHENOMENON

= unaccomplished action effect = resumption

of interrupted action effect This phenomenon

is the seemingly paradoxical assertion by the

Russian female psychologist Blyuma V

Zei-garnik (1900-1988) that the recall of ed/unfinished tasks is superior to the recall of completed tasks Zeigarnik is noted for her doctoral dissertation that was the first formal

interrupt-test of Kurt Lewin’s Gestalt theory concerning

the idea that attainment of a goal relieves sion In a typical experimental procedure for

ten-the Zeigarnik effect, participants are asked to

perform 15-22 different tasks; some tasks are manual (e.g., stringing beads), and some are mental (e.g., solving puzzles) On half of the activities, participants are allowed to continue until completion, but on the other half of the tasks they are asked to stop and move on to a new activity Following this phase, the task materials are removed, and the participants are asked to recall some of the activities that they had just experienced Results of this simple procedure typically show that the number of incompleted or unfinished tasks (called “I”) that are recalled is higher than the number of completed tasks (called “C”) A calculated ratio, using “I/C,” was always greater than 1.0

in Zeigarnik’s experiments In some cases, the I/C ratio was related, subsequently, to a per-son’s “ambition” level Among the possible alternative explanations that may account for

the Zeigarnik effect are that participants may

implicitly assume that the interrupted tasks will be completed at a later time; task inter-ruption may set up a new motive involving resentment toward the interrupter, which causes better memory; the interruption of a task emphasizes that task; the participant may attempt to achieve “closure” concerning the incompleted tasks; participants’ personal his-tories in being rewarded for attending to un-solved problems may lead to better memory; and fulfillment and completion may be de-fined differently by different persons in terms

of their own sense of satisfaction Studies

show that the Zeigarnik effect is less likely to

occur if the participant is ego-involved in the task, and is most likely to occur if the individ-ual has a genuine level of aspiration in the interrupted task (i.e., the task is possible of being achieved ultimately) Other studies indi-cate that the differential effect between the I and C tasks seems to be quite temporary (typi-cally being lost over a period of 24 hours), and does not occur with all types of tasks See also

GESTALT THEORY/LAWS; LEWIN’S

FIELD THEORY

REFERENCES

Zeigarnik, B (1927) Untersuchungen zur

handlungsund affekpsychologie

Herausgegeben von K Lewin, 3

Das behalten erledigter und

unerele-digter handlung Psychologische

Forschung, 9, 1-85

Freeman, G (1930) Changes in tonus during

completed and interrupted mental

work Journal of General

Psych-ology, 4, 309-333

Pachauri, A (1936) A study of Gestalt

prob-lems in completed and interrupted

tasks British Journal of Psychology,

27, 170-180

Prentice, W (1944) The interruption of tasks

Psychological Review, 51, 329-340

Glixman, A (1949) Recall of completed and

incompleted activities under varying

degrees of stress Journal of

Ex-perimental Psychology, 39,

281-295

Reeve, J., Cole, S., & Olson, B (1986) The

Zeigarnik effect and intrinsic

moti-vation: Are they the same?

Motiva-tion and EmoMotiva-tion, 10, 233-245

ZEILER’S THEORY See SPENCE’S

THE-ORY

ZEISING’S PRINCIPLE This

generaliza-tion refers to a term - golden secgeneraliza-tion - that was

used by the German mathematician Adolph

Zeising (1810-1876), and called attention to

the aesthetic value of the geometric

relation-ships inherent in a rectangle That is, the

golden section is the division of a line or area

into two parts, or the relations of the sides of a

rectangle, in such a manner that the ratio of

the smaller to the larger equals the ratio of the

larger to the whole This principle of

propor-tion was investigated experimentally by the

German physicist/mathematician/philosopher

Gustav Fechner (1801-1887) in the area called

experimental aesthetics Fechner’s seminal

re-search on preferences for shapes gave

experi-mental aesthetics its “reductionistic” quality

(i.e., examining aesthetics from “below” from

a structural point of view) Investigations have

been made by researchers for an aesthetic

formula (cf., Birkhoff, 1933) In one case, the

aesthetic measure (M) of balance or unity (represented by the number 1) is defined as the ratio of order (O) to complexity (C): in the resulting formula, M = O/C, the various com-ponents of an artwork can be physically speci-fied, measured, and evaluated where the closer

it is to 1, the more “harmonious” the object

Zeising’s principle attempts to answer the

per-sistent question in aesthetics concerning the dimensions of preferred shapes such as en-

compassed in the concept of the golden tion See also EYE PLACEMENT PRINCI-

sec-PLE; FECHNER’S LAW; GESTALT ORY/LAWS; WEBER’S LAW

THE-REFERENCES

Zeising, A (1855) Aesthetische forschungen

Frankfort, Germany: Breitkopf & Haertel

Zeising, A (1884) Der goldene schnitt

Leip-zig: Breitkopf & Haertel

Fechner, G (1897) Vorschule der aesthetik

Leipzig: Breitkopf & Haertel Archibald, R C (1920) Notes on the loga-

rithmic spiral, golden section, and the Fibonacci series In J Ham-

bridge (Ed.), Dynamic symmetry

New Haven, CT: Yale University Press

Birkhoff, G (1933) Aesthetic measure

Cam-bridge, MA: Harvard University Press

Valentine, C (1962) The experimental

psy-chology of beauty London:

Methu-en

Zusne, L (1970) Visual perception of form

New York: Academic Press

Hintz, J M., & Nelson, T M (1976) Golden

section: Reassessment of the

peri-metric hypothesis American nal of Psychology, 83, 126-129

Jour-Child, I (1978) Aesthetic theories In E

Car-terette & M Friedman (Eds.),

Handbook of perception Vol 10

New York: Academic Press

Plug, C (1980) The golden section

hypoth-esis American Journal of ogy, 93, 367-387

Psychol-McWhinnie, H J (1987) A review of

se-lected research on the golden

sec-tion hypothesis Visual Arts search, 13, 73-84

Re-Davis, S T., & Jahnke, J C (1991) Unity

and the golden section: Rules for

aesthetic choice? American Journal

of Psychology, 104, 257-277

ZEITGEIST THEORY See

NATURALIS-TIC THEORY OF HISTORY

ZEN BUDDHISM See BUDDHISM/ZEN

BUDDHISM, DOCTRINE OF

ZENO, ACHILLES ARGUMENT OF The

Greek philosopher Zeno of Elea (early 5th

century B.C.) was the author/originator of the

sophism (i.e., a clever and plausible but

falla-cious argument or form of reasoning) called

the Achilles argument to prove, theoretically,

that motion is impossible According to the

argument, Achilles (who was the fastest

pos-sible runner) could never overtake the tortoise

(who was the slowest moving animal) if the

tortoise had ever so short a start The

reason-ing behind the argument is that because the

distance between them consists of an infinite

series of parts, and when Achilles, by

travers-ing one of these parts, comes to where the

tortoise was, the latter will always have gone

further A variation on Zeno’s famous

“Ach-illes-tortoise” philosophical paradox or

sce-nario is the equally-paradoxical or specious

argument that an arrow shot from a bow will

never truly reach its target because,

theoreti-cally, it will always have gone only half the

existing distance to the target at any given

moment See also PROBLEM-SOLVING

AND CREATIVITY STAGE THEORIES

REFERENCE

Baldwin, J M (Ed.) (1901-1905) Dictionary

of philosophy and psychology New

York: Macmillan

ZIPF’S LAW This proposition was

devel-oped by the American philologist George

Kingsley Zipf (1902-1950), and states that an

equilibrium exists between uniformity and

diversity in examining various psychological

phenomena In general, Zipf’s law describes

the relationship between the frequency with

which a certain event occurs (e.g., the

fre-quency of usage of a word in a language) and

the number of events that occur with that

fre-quency In particular, Zipf’s law states that

when examining certain aspects of language,

it is predicted that there are a very large

num-ber of very short words (e.g., “auto”) that

occur with high frequency and progressively

fewer longer words (e.g., “automobile”) that

occur with lower frequency Zipf sized that such uniformities or “tendencies” in language usage are the result of a biological

hypothe-principle of least effort Although this latter

notion has not been validated by other searchers (these uniformities are now known

re-to be merely the necessary result of particular

stochastic processes), Zipf’s linguistic pothesis that frequency of word usage and

hy-word length are inversely related seems to be

a pervasive phenomenon of language usage, especially in the present age of computers and the perceived need for rapid communication See also LEAST EFFORT, PRINCIPLE OF

REFERENCES

Zipf, G K (1935) The psycho-biology of

language Boston: Houghton

Mif-flin

Zipf, G K (1945) The repetition of words,

time-perspective, and semantic

bal-ance Journal of General ogy, 32, 127-148; 33, 251-256

Psychol-ZOLLNER/POGGENDORFF ILLUSION

See APPENDIX A

ZOMBIISM THEORY The phenomenon of

zombiism (i.e., a corpse-like/robot-like human

being believed to belong to the “living dead,” who is buried alive and resurrected by witch-doctors in order to carry out their directives, existing in particular in the voodoo cult of Haiti and various West African religions) has been studied by the Irish-Canadian ethnobi-

ologist E Wade Davis (1953- ) In his biism theory, Davis suggests that in the secret

zom-cult activities the ingestion by the victim of a barely sub-lethal dosage of a poison/magic powder (consisting of such substances as pufferfish and other ingredients containing the neurotoxin tetrodotoxin) results in a deep coma resembling death The witchcraft cere-monies also typically involve a live burial where, along with the poison, extensive neuro-logical damage usually occurs in the victim Later, when the victim is exhumed/revived, he

or she typically has few intact memories or