Possible impactive factors on theory of mind of vietnamese children

This study tested others’ belief-desire understanding in seventy-seven Vietnamese children at the age between six and eight, and aimed to find out the relationship between children’s per

Running head: POSSIBLE IMPACTIVE FACTORS ON THEORY OF MIND

Possible Impactive Factors on Theory of Mind of Vietnamese Children

An T Nguyen University of Erfurt, Germany

Journal: Child Development

Author Note

This manuscript reports a study that was conducted for the fulfillment of the requirements

of the author’s master thesis at the University of Erfurt The work was written according to the APA guidelines, apart from the tables and figures that are inserted directly in the text

Correspondence concerning this article should be addressed to Thuy An Nguyen who is currently working at Faculty of Education, University of Social Sciences and Humanities,

Vietnam National University Hochiminh City, 10-12 Dinh Tien Hoang, Ben Nghe Ward, District

1, Hochiminh City E-mail: mgthuyan.nguyen@gmail.com

Abstract

Others’ belief-desire understanding is an important ability of theory of mind However, research across cultures has mostly investigated children’s false-belief understanding (Frank & Temple, 2009; Callaghan et al., 2005) There was a lack of study investigating belief-desire understanding

in non-Western cultures This study tested others’ belief-desire understanding in seventy-seven Vietnamese children at the age between six and eight, and aimed to find out the relationship between children’s performance in three-location false-belief avoidance tasks and three possible affective factors including age, inhibitory control and parenting styles Findings revealed the universal developmental trajectory from below- to above-chance in Vietnamese children The developmental timing and mechanism were, however, different between Vietnamese children and Western children Hypotheses about the relations between belief-desire understanding and inhibitory control; belief-desire understanding and parenting styles were partly confirmed Our results support the findings in previous cross-cultural studies (e g Liu, Wellman, Tardif, & Sabbagh, 2008; Wellman, Cross & Watson, 2001) and indicate the need of further investigation not only on mechanism underlying children’s performance, but also on social and cultural factors that have not yet been revealed

Key words: Theory of mind, belief-desire understanding, age, inhibitory control,

parenting styles, elementary school aging

Possible Impactive Factors on Theory of Mind of Vietnamese Children

The term “Theory of Mind” (ToM), which was firstly used by Premack and Woodruff in

1978, has quickly become an important theoretical construct and the topic of substantial research effort in psychology (Wellman et al., 2001).This term refers to “the ability to reason about

mental states, such as beliefs, desires, and intentions, and to understand how mental states feature

in everyday explanations and predictions of people’s behavior” (Apperly, 2012, p 826)

Exploring the role of ToM to social life, research on ToM did demonstrate implications of ToM for different aspects of life Latz (2002) explored e g that difficulties in reasoning others’

mental states were found to be responsible for deficits of social interaction ability in children with an autism spectrum disorder Mental states understanding capacity of people with

schizophrenia was also claimed to be a powerful predictor for their social competence (Henry, Phillips, Ruffman, & Bailey, 2013) Moreover, there are not only interesting results for people with special needs but also for everybody because each and every needs ToM to understand, to explain and to predict behavior (Doherty, 2009) According to this, research on typical ToM development indicated that individual differences in ToM have definite implications for

academic skills as well as educational achievement, and in particular, for social competencies such as the ability to instruct information in conversation and to communicate successfully (Henry et al., 2013; Patnaik, 2008, Krych-Appelbaum et al., 2007)

Decades of research largely investigated to uncover questions of when and how ToM develops Among a variety of methods which were devised to measure performance of ToM, the false-belief task is the most widely used to test ToM in humans (Apperly, 2012; Liu et al., 2008) One of the most common was termed the “unexpected location” task In this one, typically, participants will see a protagonist who firstly puts an object in a location (says A) and then goes

outside During the absence of the protagonist, the object will be moved from the location A to other location (for example, location B) Participants are then explicitly asked to judge a think question “Where the protagonist thinks the object is?”, or a predict question “Where the

protagonist will look for the object at his return?” Correctly answering these questions,

participants have to assume that the protagonist still believes that the object is in the location A because he did not witness the moving of the object That means they have to understand the distinction between what they have seen in the scenario and what the protagonist knows about the location of the object In brief, they have to realize that thoughts and beliefs might not reflect the real state of the world (Mayer & Träuble, 2013) Most of children at three years failed the task, whereas most of four to five year-old children gave the correct answer (Sodian, 2008; Wimmer & Perner, 1983).Yet, recent studies using spontaneous-response tasks – e g violation-of-expectation (VoE) or anticipatory looking (AL) – reported the false-belief understanding at younger ages (Baillargeon, Scott & He, 2010; Onishi & Baillargeon, 2005) These different findings pose again questions about the emergence of false-belief understanding in infant and early childhood Thus, there is the possibility that younger children than four or five year-olds do understand false beliefs Perhaps it depends on the underlying method to what extent the

presence of ToM can be detected in younger children The development of new method makes sense and should be considered

Besides the standard false-belief tasks, avoidance false-belief task (or “avoidance task”) was also applied to study ToM In this task children have to avoid, instead approach, the target Assuming that a protagonist sees how a dog jumps into one location (calls belief-location or B-Location) and then leaves the room While he is outside, the dog jumps from this location to the other location (dog-location or D-Location) As the protagonist returns, he wants to put his cat to

a location but wants to avoid the dog as well, because the dog can hurt his cat At this test

scenario, participants were then asked “Where will the protagonist try to put his cat?” To answer correctly this question participants not only have to understand about the protagonist’s false-belief and his avoidance desire, but also have to execute “double inhibition” One inhibition is to ignore participant’s own true belief The other inhibition is to avoid the B-Location and choose the D-Location (Friedman & Leslie, 2004) Thus, the avoidance task is presumably more

difficult than the standard false-belief task (Hiatt & Trafton, 2010; Friedman & Leslie, 2004) Four year-old children, who passed the standard false-belief tasks, failed the avoidance task At the age around six years old, children were found to be able to master this task with verbal

measures (Buttelmann & Buttelmann, in press; Hiatt & Trafton, 2010; Leslie et al., 2005) The improvement from passing the standard false-belief tasks to passing the avoidance tasks was announced as the second developmental shift, after the first developmental shift at the age

around four Experiments using spontaneous-response avoidance tasks have not been conducted, however

Additionally, Friedman and Leslie (2004) used three-location avoidance false-belief tasks to test the belief-desire understanding with children and adults In their scenario there is one empty location (called the neutral location, or N-Location), which never contained the dog the entire time, besides the belief-location (B-Location), and the dog-location (D-Location) Thus, there are two correct answers for the question “Where the protagonist will put the bone, while avoiding the dog?” First, a proper answer would be the location containing the dog, and second the empty location The authors found that children at the age between four and eight preferentially chose D-Location, whereas adults showed the opposite bias of choosing N-

Location That indicates that there is a developmental shift between children at the age of eight and adults (Friedman & Leslie, 2004)

Modifying an existing avoidance task, Buttelmann and Buttelmann (in press) examined the belief tracking in children and adults They manipulated beliefs of the protagonist in order to have two conditions In true-belief condition, the protagonist witnessed all switches of a dog In false-belief condition, however, the protagonist was absent during the dog’s final jump They found that adults typically chose N-Location, while children at six years old preferred to choose N-Location than B-Location only in false-belief condition and chose randomly these two

locations in true-belief condition Results demonstrated that children and adults automatically tracked the protagonist’s beliefs, although these beliefs were not necessary to solve the tasks In the present study, we also used the three-location avoidance tasks to test children’s belief-desire understanding

Cumulative findings for questions when and how ToM develops in children demonstrated that the development of ToM and particularly the development of false-belief understanding are age-related Conducting a meta-analysis of 178 studies, Wellman and his colleagues (2001) pointed out that the odds of being correct in false-belief tasks increase 2.94 times, for every one-year increase in age In the same manner as that, Liu and his team (2008) carried out a meta-analysis of 196 studies about false-belief understanding in a population of non-Western children speaking non-Indo-European languages, e g Mandarin and Cantonese They found that the odds

of being correct increase 4.32 times for every one-year increase in age Thereby, the Chinese developmental trajectory of false-belief understanding did not change, although Chinese think-falsely verbs were used in questions Totally, the overall developmental trajectory from below-

to above-chance performance for belief understanding is claimed to be universal, and

false-belief tasks are measuring the same construct across cultures (Liu et al., 2008; Wellman et al., 2001) Unfortunately, these meta-analyses did not obtain studies using avoidance tasks

However, due to previous findings concerning avoidance tasks, we expect that children’s desire understanding still develops in the same way – from below- to above-chance performance – and is also proportionalto age In this vein, we would like to examine the relation between Vietnamese children’s belief-desire understanding performance and their age in the current study

belief-Inhibitory Control

Besides the robust relation to age, there are evidences which indicate the correlation between the performance of ToM and the inhibitory control (e g Carlson & Moses, 2001; Perner & Lang, 1999; Frye, Zelazo, & Palfai, 1995) The term “Inhibitory control” (IC) is

defined as “the capacity voluntarily to inhibit or regulate prepotent (i.e., strong or automatic) attentional or behavioral responses” (National Survey of Child and Adolescent Well-Being,

2009, p 1) It refers to the ability to focus on appropriate stimuli in the presence of inappropriate stimuli and to countermand strong but irrelevant behavioral tendencies Carlson and Moses (2001) explored a high relation between ToM and the IC (r =.66, p < 001) in their study with three- to four-year-old children on ten inhibitory control tasks and four ToM tasks Additionally, the authors found that this relation is two-way That means children’s performance in every IC task significantly related to each of their ToM score and, in turns, every ToM scores has a

significant relation with the IC measure This relation remained significant even when the age, gender, verbal ability, motor sequencing, family size, and performance on pretend-action and mental state control tasks were controlled (Carlson & Moses, 2001) Furthermore, the ability of

IC can predict the performance in false-belief tasks better than other common factors as working

memory, intelligence or age can do (Carlson, Moses, & Breton, 2002) In addition, the difficulty level of IC was found to play an important role in the link between executive functions and ToM (Wei, Wu, Li, Feng, & Zelazo, 2005) In a longitudinal study conducted by Flynn (2007), the majority of children were found to own firstly a good formed IC, before they hold ToM The correlation between ToM and IC was also confirmed in a study comparing three groups of

children: children with attention deficit hyperactivity disorder (ADHD), autistic children and children without special needs Typically, autistic children and ADHD children have difficulties not only in ToM tasks, but also with the IC ability (Yang, Zhou, Yao, Su, & McWhinnie, 2009) The causative relation between the IC ability and ToM performance could be clarified in the light of the modularity theory As mentioned before, the demand of inhibition in solving a false-belief avoidance task makes this task more difficult than a standard false-belief task Children, who are able to inhibit their own true-belief and the tendency of choosing the belief-location, are able to pass a false-belied avoidance task Thus, the ability of IC is very necessary for the

emergence and the development of belief-desire understanding (Friedman & Leslie, 2004)

In 2006 Sabbagh and his research team carried out a comparison between Chinese and American children about the development of ToM and executive functioning Findings showed that there is a relation between executive functioning and ToM in Chinese children Chinese children were even better in executive functioning than U S children, although they were not better in ToM performance than their U S peers Thus, the relation between ToM and executive function within a culture exists not only in Western context, but also in non-Western context Sabbagh and colleagues (2006) suggested for future studies exploring ToM and IC between cultures to consider relevant experiential factors as well In sense of the within-culture aspect, we want to investigate in the present study the IC ability of Vietnamese children We also expect to

find out the significant relation between their IC ability and their performance in belief-desire understanding, which have not yet indicated in previous studies

Parenting Styles

Recent studies, especially cross-cultural studies, stated that the social factors can

influence the development of children’s ToM It was suggested to consider relevant experiential factors in explaining individual differences in ToM (Liu et al., 2008; Lu, Su & Wang, 2008; Sabbagh et al., 2006) Research has shown a relatively stable effect of talking about mental states

on the children’s ToM development in Western cultures For example, forty month-old children performed better on false-belief tasks if they came from families that frequently discussed

feelings and the ways that feelings motivate behavior (Dunn, Brown, Slomkowski, Tesla, & Youngblade, 1991) Adrián, Clemente and Villanueva (2007) found if mothers do use mental verbs (like “think”) during story-telling, children’s understanding of mental states will be

facilitated Relations between children’s ToM development and mother-child mental state talk were found concurrently and longitudinally across the preschool years (e g Adrián et al., 2007, Dunn et al., 1991) Moreover, mental state talk between mothers and children was confirmed to

be a better predictor of children’s ToM in comparison with children’s verbal ability and

emotional understanding (Lu, et al., 2008)

Furthermore, the facilitation of mental state talk in the family on children’s ToM

development was examined in non-Western context, such as in China Interesting, ToM

performance of Chinese children was not facilitated by talking about mental states, instead, by talking about others during autobiographical memory (Lu et al., 2008) Thus, any interaction between parents and children, hereby talking either about mental states or about others,

correlates with children’s ToM development Nevertheless, we are aware of no studies in which

the relation between parenting and ToM development has been investigated directly, whereas parenting is traditionally known to play an important role in education and consequently in cognitive and socio-emotional development of the child (e g Gray & Steinberg, 1999;

Baumrind, 1991) Parenting style was defined as “the emotional climate in which parents raise their children” (Darling & Steinberg, 1993, as cited in Spera, 2005, p 127) and was

characterized by Baumrind (1991) by dimensions of parental responsiveness and demandingness Decades of research of parenting styles consistently indicated that parenting style, which

balances between clear or high parental demands and emotional responsiveness and recognition

of child autonomy, was considered to be one of the most consistent family predictors of

competence from early childhood through adolescence (Darling, 1999) In particular, children whose parents have not only high responsiveness but also high demandingness, are highly able to have a sense of strong personal value (Derzon & Sale, 2001, as cited in Hasnain, Faraz &

Adlakha, 2013), and are more likely to develop high self-esteem, positive self-concept, greater self-worth (Sarac, 2001) Because of the existing of the interaction link between self-concepts and ToM or false-belief understanding (Ahn & Miller, 2012; Burbrigde, 2011, Háppe, 2003), we question about the likely influence of parenting styles on children’s belief-desire understanding and want to investigate on this question in the current study We expect that parenting styles and children’s performance in belief-desire understanding tasks correlate with each other

The Present Study

In the present study, we firstly tested the belief-desire understanding of Vietnamese children with three-location false-belief avoidance tasks Then, we examined the relation

between children’s ToM performance with age, inhibitory control and parenting styles

Vietnam is a country in Southeast Asia and has been strongly influenced by Confucian culture, which emphasizes on connectedness, harmony and interdependent, instead independent (Moriguchi, Evans, Hiraki, Itakura, & Lee, 2012) Of Vietnamese children is expected that they learn to “respect order” (tôn ti trật tự), to know their inferior position in society and showing deference to their superiors In response to increased economic requirements a majority of

parents have to work long hours and left their children at learning groups or alone at home

without adult supervision (Tran, 2013) Regarding with findings of cross-cultural differences in children’s cognitive representations of self and others (Lu et al., 2008), and realizing that studies

in non-Western cultures often obtained only Chinese, Japanese or Korea data, we conducted this study with Vietnamese children at age between six and eight The following hypotheses were tested:

(a) Vietnamese children at the age between six and eight were expected to pass the avoidance tasks and to show biases in choosing locations as their peers in Western cultures do

(b) The belief-desire understanding performance of Vietnamese children was proposed to increase parallel with age increasing Older children were expected to outperform their younger peers

(c) Children’s performance of belief-desire understanding was also expected to be

proportional to the inhibitory control ability That means children who perform better in belief avoidance tasks should have greater scores in inhibitory control tasks

false-(d) High responsiveness and high demandingness score in parenting styles were expected

to have positive relations with belief-desire understanding performance of children

Method Participants

Parents with elementary school children were recruited in small private learning groups

in the city of Bien Hoa, Vietnam Since the study was conducted during the school holiday, we could not reach children through the schools Altogether about four hundred letters for

participation were handed out Seventy-seven parents consented their children to participate in our study One parent of each child was asked to answer two questionnaires about the parenting

styles We received sixty-four answers from the parents (15 fathers and 49 mothers, M = 37.61 years, SD = 6.86)

Seventy-seven Vietnamese children (34 boys and 43 girls) participated in the study The

age of children ranged from 5.60 years to 8.10 years (M = 6.723 years, SD = 0.625) Due to

missing data, two children were excluded from the analysis All children are Vietnamese citizens and speak Vietnamese as mother language

Measurement

Belief-desire understanding The tasks to measure children’s belief-desire

understanding performance were modified from the experiment used by Buttelman & Buttelman (in press) The original experiment consisted of two parts: one with agent and the other with a pile of blocks It was presented on computers using E-Prime 2.0 The agent and the pile of blocks were matched in colors and were presented in the upper left corner of the screen, while three boxes (three locations) were lined up at the bottom of the screen The agent and the pile of

blocks always left and entered the screen through the right side of the screen Their movements were identical throughout

Each task’s trial comprised two phases In the presentation phase, the dog appeared and firstly sat down in front of a box (the neutral box or N-Box), then jumped into the other boxes twice times The agent and the pile of blocks could witness the first jump of the dog into one box (the belief-box or B-Box) During the dog’s second jump into the last box (the dog-box or D-Box) the presence of the agent and of the pile of blocks was manipulated to have two conditions

In the true-belief condition the agent and the pile of blocks watched every switch of the dog, and therefore knew that the dog was in the D-Box at the end In the false-belief condition they were absent during the dog’s final movement, and consequently held a false belief about the final location In the response phase, a cat would appear in the middle of the screen Children were asked to put the cat into one of the boxes as quickly as possible by clicking on the box while avoiding the box containing the dog, because it might hurt the cat

In our study we replicated this experiment, but changed the agent; and called it the self task Additionally, we constructed the other and the implicit tasks basing on the self task, since

we also wanted to use explicit- and spontaneous-response measurements to test children’s desire understanding As each child received these three tasks after each other, and we did not want a transfer effect between these tasks, three different animate drawn girls were used as protagonists Their hair colors were adapted in the context familiar to Vietnamese children Protagonists were changed randomly through the tasks and the change orders were

belief-counterbalanced between participants as well Each protagonist is accompanied with a pair of bad and good animals and a set of locations: dog – cat and boxes, fox – rabbit and bins, duck – snake and hampers In the same manner like the experiment of Buttelmann and Buttelmann (in press), we named the location, which never contained the bad animal, the N-Location; the

location containing the bad animal at the end of trial the D-Locaiton; and the rest location the Location

B-In the scenario of the other and the implicit tasks we used one grey wall with a hole in the upper middle as the background and three doors direct behind the locations The protagonists stood behind the wall but at the position of the hole, so they could see movements of the bad animals To reach the locations, the protagonist had to go through the doors In the response phase good animals appeared on the hands of the protagonists

For each task we had different questions for children In the self task, children were asked

to choose a location, where they can put their own good animals into but avoid the bad animals Whereas children were told in the other task that the good animals belong to the protagonists and they should choose the location, where the protagonists would put their animals into, while avoiding the bad animals Using the spontaneous-response measurement in the implicit task, we instructed children in the same way as in the other task, but then asked children just to watch the action of the protagonists The protagonists’ actions were illustrated by congruent or incongruent pictures, in which the protagonists and their good animals on their hands stood at the position of the locations

The number of trials and their duration changed from task to task While there were six trials in each true-belief and false-belief condition for the self and other tasks; there were only three ones per condition for the implicit task One trial of self task lasted forty two seconds from the beginning until the response screen, whereas the duration of one trial in other tasks was twenty nine seconds In the implicit task, the presentation phase took also twenty nine seconds, but the response phase lasted in twenty seconds

Children’s choice of location (N-, B- and D-Location) and reaction times in the self and other tasks were recorded with E-Prime 2.0 experimental software Since children had three locations to choose in each trial and there was one location considered as wrong varying cross the tasks and the belief conditions, the possibility of making failure per trial by chance was 33.33% The looking behavior of the children in the implicit task was recorded with a camera placed behind the monitor The looking time (maximal twenty seconds) on the screen was

calculated in percentage If children looked at the screen at the beginning of the response phase, the looking time would be divided for twenty When they did not look at the screen from the beginning of the response phase, the looking time would be calculated in regard with the time children began to look at the screen to the end of the response phase The first look away was scored in seconds

Inhibitory control Measuring children’s inhibitory control ability we applied the

Dimensional change card sort (DCCS) task and the task “Hüpfen - Flattern” In the DCCS task (Frye et al., 1995), children were instructed to sort sixteen cards depicting either a red dog or a yellow fish into two white trays, one with a red fish in the front and the other with a yellow dog

in the front The order of the sorting rules was counterbalanced between children Thirty nine children were asked to sort cards according to the shape first The rest of children became the task sorting cards according to the color first The score was the percentage of correct postswitch sorts that clearly indicated children was following the new rule (Sabbagh et al., 2006)

The task “Hüpfen - Flattern” was designed by Buttelmann (2014) We translated the task’s instruction from German to Vietnamese In this task children were asked to jump and flap according to the experimenter’s instruction There were a familiar phase (ten trials) and a test phase (sixteen trials) During the familiar phase, children had to jump up and keep their arms

straight along their bodies, when they heard the word “nhảy” (or “hüpfen” in German, “jump” in English) In contrary, children should stand quietly and flap their arms, even when they heard

“vỗ” (or “flattern” in German, “flap” in English) In the test phase, children had to act

contrastingly with the familiar phase That means, they would flap when hearing “nhảy”, and jump when hearing “vỗ” The score was the number of children’s correct reactions in the test phase The test phase was recorded with a camera

Parenting styles Two appropriate questionnaires were used to collect data about

parenting styles from parents with elementary school children Both questionnaires were

translated from German into Vietnamese

First, we applied the questionnaire “Eltern-Erziehungsstil-Inventar” (EEI) that was

constructed by Satow (2013) This questionnaire consists of four basic dimensions: love,

strictness, independence, religiousness; and two supplementary dimensions: cooperation with partner, and cooperation with school In sum the EEI comprises fifty four items Each basic dimension has ten items, while there are seven items in each supplementary dimension The Cronbach’s Alpha of each dimension lies between 71 and 93 That illustrates the good and very good reliability Parents or caregivers give their answers on a four-level Likert scale with 1 means strongly disagree (“trifft gar nicht zu”), 2 for disagree (“trifft eher nicht zu”), 3 for agree (“trifft eher zu”), and 4 means strongly agree (“trifft genau zu”) (Satow, 2013)

Second, we used the questionnaire “Deutsche erweiterte Version des Alabama Parenting Questionnaire für Grundschulkinder” (DEAPQ-EL-GS) to measure parenting styles This forty-item questionnaire was constructed by Reichle and Franiek (2009) The authors translated, adapted and extended the original questionnaire to measure the dimension of positive parenting behavior, involvement, (poor) monitoring, inconsistent discipline, and corporal punishment

They also added two dimensions including authoritarian parenting and responsible parenting in their questionnaire With stabilities from r = 57 to r = 77 the psychometrical properties were found to be good to satisfactory Seven dimensions could account 51% of the total variance of items A five-level Likert scale was used to score statements in this questionnaire, with 1 for almost never (“fast nie”) and 5 for almost always (“fast immer”) (Reichle and Franiek, 2009)

From ninety four items of these two questionnaires we chose fifty items and sorted them into two dimensions responsiveness and demandingness Their Cronbach's Alphas are 85 and 76 Since two different Likert scale were used in two questionnaires, the total scores of two dimensions responsiveness and demandingness were calculated as the average scores of these dimensions in each questionnaire The average score of each dimension was used to analyze their relations with other variables

Procedure

In cause of difficulties in directly reaching parents, we gave invitation letters, which describe the purpose of our study and enquire the participation of parents and their children, to the teachers of the private learning groups Teachers gave these letters further to parents of their students Then, we received the answers of parents through the teachers Moreover, teachers helped us to arrange appointments with children, since we needed not only permissions of

parents but also of teachers to test children

Children were tested individually in a forty-minute session Except the greeting phase, the test consisted of three ToM tasks and two inhibitory control tasks These tasks were

alternately conducted The order of tasks was the self task, the task “Hüpfen - Flattern“, the other task, the DCCS task, and the implicit task All instructions were translated from German into Vietnamese

Children were randomly assigned to one of two groups in the self task (either with an agent or with a pile of blocks) and in the DCCS task (sorting the cards either according to shape first or according to color first)

Results Belief-desire Understanding

To conclude children’s performance in belief-desire understanding we conducted three types of tasks: the self task, the other task and the implicit task In the self and other tasks we analyzed children’s choice of location and their reaction times In implicit task we measured

children’s looking duration on screen One-way analyses of variance and t-Tests were used to

determine whether children pass the tasks, and whether they show a bias in choosing the

N-Locations in the self and the other tasks Then, we applied two-way analyses of variance and

t-Tests to compare children’s performance between these three tasks

Self task First, we analyzed children’s choice of location Conducting a

Repeat-Measures ANOVA with Greenhouse-Geisser correction, we found no interaction effect between types of protagonist (the agent and the pile of blocks) and the choice of location in two belief-

conditions (F N-Box (2,73) = 0.196, p = 822, ηp 2 = 005, F B-Box (2,73) = 0.196, p = 822, ηp 2 = 005,

F D-Box (2,73) = 0.156, p = 856, ηp 2 = 004) Therefore we combined data for both protagonist types in the further analyses

Most of children passed the self task in both belief-conditions (87% of children in the false-belief condition, and 76.6% in the true-belief condition) Testing their failure against

chance level (33.33%) we found significant effects in both belief-conditions (tfalse-belief(75) =

-19.012, p < 001, d = - 2.181; ttrue-belief(76) = - 10.288, p < 001, d = - 1.172) A t-Test revealed a

significant effect between two belief-conditions (t(76) = 3.003, p = 004, d = 1.58), so children

performed significantly better in the false-belief condition than in the true-belief condition

Comparing the choice of and B-Location, we found that children chose the

N-Location significantly more often than the B-N-Location in both belief-conditions (tfalse-belief(75) =

3.72, p < 001, d = 0.853; ttrue-belief(76) = 2.33, p = 022, d = 0.531) However, their choice of the N-Location did not significantly differ between belief-conditions (t(75) = 0.345, p = 731, d =

0.219) The same finding was found in comparing children’s choice of the B-Location between

both belief-conditions (t(75) = - 0.345, p = 731, d = - 0.219)

Second, we utilized children’s reaction times between belief-conditions Trials with a response time that was out of the range of the mean plus/ minus two standard deviations were removed from analyses Children needed significantly more time in the true-belief condition than

in the false-belief condition (t(75) = 2.477, p = 16, Mdifference = 274.83 milliseconds, d = 0.186) The response time in the first trial between two conditions was not significantly different (t(58) =

- 1.433, p = 157) There was no significant correlation between reaction times and choice of

location across the conditions

Other task First, we present the results for children’s choice of location Testing against

chance level (33.33%) children performed significantly better than by chance in true-belief condition, while their performance was significantly poorer than by chance in false-belief

condition (ttrue-belief(76) = 14.503, p <.001, d = 1.653; tfalse-belief(76) = - 3.323, p = 001, d = -

0.379)

In both belief-conditions, children chose the N-Location significantly more than the other

correct options (tfalse-belief(76) = 16.580, p < 001, d = 1.889; ttrue-belief(76) = 2.934, p = 004, d =

0.334) Moreover, they chose the N-Location more often in the false-belief condition than in the

true-belief condition (t(76) = 9.634, p < 001, d = 1.097)

Second regarding reaction times, children needed more time in the false-belief condition

than in the true-belief condition; however, this difference was insignificant (t(75) = 1.423, p = 159, Mdifference = 226.013 milliseconds)

Implicit task In contrary our expectation, no difference of the overall looking time and

the first look away between congruent and incongruent events was found (overall looking time:

tfalse-belief (76) = 0.043, p = 966, Mdifference = 0.129%; ttrue-belief (76) = 0.259, p = 797, Mdifference =

0.603%; First look away: tfalse-belief (70) = 0.462, p = 645, Mdifference = 0.4296 milliseconds; t

true-belief (73) = - 0.301, p = 764, Mdifference = 0.2297 milliseconds) That means, children looked at the

screen as long as they wanted regardless with what happened in the scene

Children’s performance between different avoidance tasks Conducting a 3 x2-

Repeated-Measures ANOVA, we found a main effect of the task, a main effect of condition, and

a task x condition interaction (F task (2,152) = 31.313, p < 001, ηp 2 = 292; F condition (1,76) =

20.582, p < 001, ηp 2 = 213; F task xcondition (2,152) = 33.144, p < 001, ηp 2 = 304) Whereas most

of children passed the self task in both belief-conditions, they failed in the implicit task In the other task children performed differently between two belief-conditions Most of them passed in the true-belief condition, but failed in the false-belief condition (see Figure 1)

Figure 1 Children’s performance in three avoidance tasks The points represent the percentages of

children who succeeded in these tasks, according to conditions

Since we used the same measurement in the self and the other tasks, we focused on comparing children’s performance in these two tasks There are a crossover interaction between the belief-conditions and the tasks Children became better in the true-belief condition cross the self and other tasks, while their performance got worse in the false-belief cross these tasks Comparing the children’s choice of N-Location between the self and the other tasks, we found a significant difference between the frequencies of choosing N-Location in the false-belief

condition cross these two tasks (tfalse-belief (75) = - 10.006, p < 001) Children chose however Location insignificantly differently in the true-belief condition cross two tasks (ttrue-belief (76) = - 0.020, p = 984) (see Figure 2)

N-Figure 2: Results of children’s choosing locations in self and other tasks The bars represent the mean

percentages of trials in which children chose either the N-Location or the other correct options, separated according to condition Values within the bars represent the exact mean percentages

Additionally, we analyzed reaction times cross the self and the other tasks We found a

main effect of the task and a crossover interaction of task x condition (F task (1,74) = 10.722, p = 002, ηp 2 = 127; F condition (1,74) = 0.131, p = 719, ηp 2 = 002; F task xcondition (1,74) = 9.696, p = 003, ηp 2 = 116) Children reacted significantly longer in the true-belief condition of the self task than in the true-belief condition of the other task, while their reaction times in the false-belief condition were not significantly different between both tasks (see Figure 3)

True-belief condition

False-belief condition

True-belief condition

N-Location Other correct options

Figure 3 Average reaction times (in millisecond) of children in the self and the other tasks

In sum, children’s performance varied cross three avoidance tasks Most of children passed the self task and failed in the implicit task In the other task, they were successful in the true-belief condition, but were unsuccessful in the false-belief condition We found a bias of choosing the neutral location (N-Location) in the self and the other tasks

Inhibitory Control

To conclude children’s ability in inhibitory control, we firstly applied t-Tests to

determine their performance in the DCCS and the “Hüpfen – Flattern” tasks Then, we used the Pearson correlation coefficient and the binary logistic regression to examine and to predict the relation between the performance in inhibitory control tasks and children’s age The Pearson correlation coefficient was also used to test the correlation between performance of children in the DCCS and “Hüpfen – Flattern” tasks

DCCS task Most of children passed the task in both rules (89.61% of children according

to the first rule and 86.88% of children according to the second rule) Their performance were

significant better than the chance level (50%) (tfirst rule(76) = 11.317, p < 001, M difference =

39.610%; tsecond rule(76) = 9.599, p < 001, M difference = 37.013%) There was no significant

difference between performances according to two rules (t(76) = 0.498, p = 620)

In addition, we found a significant correlation between the children’s performance

according to second rule and their age (r = 0.279, p = 014) Furthermore, the age of children was

examined as a predictor of performance regarding to the second rule A straight line equation for the data is: DCCSsecond rule = 14.509 x age – 10.525, R 2 = 0.078, indicating that the older children are, the better they performed in the DCCS task With other words, there was an effect of age on the inhibition of the first rule to sort the card according to the second rule

The task “Hüpfen - Flattern” More than the half of children passed the task (64.9% of

children) Their total performance was significantly better than the chance level (t(76) = 2.002, p

= 049, d = 0.228) Separately analyzing the performance of children in the first and the second eight trials, we found no difference (t (76) = 0.339, p = 736, M difference = 0.9740%) However, children performed significantly better than by chance in the first eight trials, while they did not

in the second eight trials (t firstrule (76) = 2.197, p = 031, d = 0.250; t secondrule (76) = 1.632, p = 107, d = 0.186)

There was a significant correlation between children’s performance in the task “Hüpfen –

Flattern” and their age (r = 0.412, p < 001) Age was also tested as a predictor of the

performance of this task A straight line equation for the data is: “Hüpfen – Flattern”total = 22.578

x age – 93.638, R 2 = 0.170 This result indicates the effect of age on the performance in the task

“Hüpfen – Flattern” Children performed better in this task as their age increased

Performances in the DCCS and the “Hüpfen – Flattern” tasks were found to correlate

with each other (r = 0.341, p = 002) However, children performed significantly better in the

DCCS task than in the task “Hüpfen – Flattern” (t (76) = 6.343, p < 001, d = 0.723)

Parenting Styles

On average, parents’ responsiveness score was 3.842, while their average demandingness score was 2.965 The answers of parents cross items within dimension were quite consistent

(SD responsiveness = 0.310; SD demandingness = 0.414) Parents’ responsiveness score was significantly

higher than their demandingness score (t (63) = 14.739, p < 001, d = 1.842) Thus, parents

showed high responsiveness and mediate demandingness with their children We found no effect

of age or of gender on their parenting styles

Correlations between Belief-desire Understanding Performance and Three Factors

including Age, Inhibitory Control and Parenting Styles

We applied the Pearson correlation coefficient to analyze the correlations between desire understanding performance cross tasks and age; belief-desire understanding performance and the performance in the inhibitory control tasks; belief-desire understanding performance and parenting styles Table 1 summarizes the results of these relations

belief-Table 1 Correlations between children’s performance in belief-desire understanding and three factors including age, inhibitory control, parenting styles

Responsive- ness

Note: N = 77 for correlations with age and inhibitory control tasks N = 64 for correlations with parenting styles

FB = the false-belief condition TB = the true-belief condition * p < 05, ** p < 001

Compared with other two independent variables, age was found to have most correlations with performance of belief-desire understanding tasks Age was negatively correlated with the percentage of failure in both belief-conditions of the self task, and positively correlated with the percentage of tracking N-Location over B-Location, as well as with the percentage of correction

in the true-belief condition of the other task That means, the older children made less mistakes

in the self task than the younger ones They were also better in the true-belief condition of the other task, and tracked N-Location over B-Location than their younger peers

Children’s performance in avoidance tasks partly correlated with their performance in IC tasks There were negative correlations between children’s scores in DCCS and “Hüpfen –

Flattern” tasks and the percentage of failure they made in the false-belief condition of the self task Thus, children who could better inhibit, outperformed their peers who have lower scores in

IC tasks In contrary to this result we found that the percentage of correction in the false-belief

condition of the other task was negatively correlated with performance in the task “Hüpfen – Flattern” That disagreement will be discussed in the next part of the work

We found no correlation between the parenting dimension responsiveness and

performance in belief-desire understanding tasks The dimension demandingness correlated negatively with children’s performance in the true-belief condition of the other task, and

positively with children’s performance in the false-belief condition of the implicit task That indicates that children, whose parents had higher scores in demandingness, performed worse in the true-belief condition of the other task, and better in the false-belief condition of implicit task This inconsistent findings will be discussed later, as well

Additionally, we run a binary logistic regression for the dependent variables of the

performance in belief-desire understanding, and the three independent variables: age, IC and parenting styles Significant results were indicated in table 2

Table 2 Binary logistic regression of children’s performance in belief-desire understanding

B S.E Wald Sig Exp(B) % variance

accounts for Self task_FB

“Hüpfen – Flattern” 0.025 0.010 6.406 0.011 1.025 8.8% - 16.4% Other task_TB

Demandingness - 2.957 1.266 5.454 0.020 0.052 10.6% - 19.1% Implicit task_FB

Demandingness 1.641 0.742 4.900 0.027 5.162 8.8% - 11.7%

Note: Predictor variables are children’s age, their performance in the task “ Hüpfen – Flattern”and parents’ score of dimension demandingness B indicates the coefficient for each predictor variable S.E indicates the standard deviation The Wald statistic and associated Sig values indicate how useful each predictor is The Exp(B) column gives an indication of the change in the predicted odds of reconviction for each unit change in the predictor variable FB = the false-belief condition TB = the true-belief condition

We could only draw a logistic regression model for three scores of the performance in belief-desire understanding According to the results, age can account for 6.3% to 11.6%

variance of children’s performance of the self task in the false-belief condition, and 12.7% to 21.2% variance of children’s performance in the true-belief condition of the other task

Increasing one year of age, the odds of success increase by a factor of 3.637 in the false-belief condition of the self task, and by a factor of 5.961 in the true-belief condition of the other task

Children’s performance in the task “Hüpfen – Flattern” can account for 8.8% to 16.4% of variance of children’s performance of the self task in the false-belief condition Rising one factor

of performance in the task “Hüpfen – Flattern”, the odds of success in the false-belief condition

of self task increase a factor of 1.025

Scores of the parenting dimension demandingness on children can account maximal 19.1% of variance of children’s performance in the true-belief condition of the other task, and 11.7% variance of children’s performance in the false-belief condition of the implicit task If scores of the parenting dimension demandingness increases by one factor, the performance of children in false-belief condition of implicit task will increase by a factor of 5.162

In general, Vietnamese children’s performance in belief-desire understanding was found correlating with age, IC and parenting styles The factor age seems to be a strong predictor of the performance in belief-desire understanding The older children are, the better they perform in avoidance tasks In the present study, we explored a relationship between children’s performance

in belief-desire understanding and IC; children’s performance in belief-desire understanding and parenting styles However, they are not consistent