EN LA CARRETERA ESTATAL

The key research question of this study is whether a person’s expression of

un/certainty for beliefs would promote young children’s mental state understanding. As the children were administered the change of location task with un/certainty first, their

performance is presented by un/certainty. First, it found no age group differences in both un/certainty groups, Mann-Whitney tests U = 218, p = .93 and U = 279, p = .57, respectively; therefore, performance on the tasks was analysed regardless of age. Figure 2.4 shows the proportion of the 3-year-old children who passed three types of FB questions including the reality question: blue bars indicate the change of location task, while green and yellow bars represent the Self and Other questions of the unexpected contents task, respectively. As mentioned above, the reality and test questions were included in the analyses. Expected frequencies were based on a chance distribution of 1/4, 2/4, 1/4 for children who correctly responded to 0, 1, 2 questions, respectively. For this and following experiments, we classified children according to whether they correctly responded to both reality and test questions or not. Thus, the expected frequencies became 3/4 and 1/4. As Figure 2.4 shows in respect of children who made correct responses to both reality and test questions, the level of chance for them was .25. The distinguishing results were that children might be aware of the different degrees of certainty by the grammaticalized markers. As shown in Figure 2.4, there were changes in the opposite direction according to the use of un/certainty markers. The children in the uncertainty group were more likely to pass the Other FB when they had experienced the protagonist’s uncertainty, whereas those in the certainty group showed a tendency of decrease on the Other FB after having heard of the certain belief.

Figure 2.4. Children’s performance on FB questions according to certainty groups. CL: Change location. FB: False belief. †p < .10, *p < .05 in tests against chance (.25).1

The task aimed to investigate whether the development of mental state understanding was influenced by the specific linguistic markers (i.e., -ci or –keyss ((-u)l ke-ya)); thus, the children’s performance was analysed by each expression. As can be seen from Figure 2.4, the children’s performance on the task showed possible influences of the linguistic markers. Binomial tests were administered in order to explore the distributions against chance levels (.25). As no age differences were observed, the tests were carried out for all the sample. The Certainty and Uncertainty on false-belief understanding (CL)

Three children were excluded due to being absent from the second session. Hence, 47 and 54 children were used in analyses of the un/certainty task, respectively. Credits were given to the children when they correctly answered the false-belief test and control questions. Thus, the scores range from 0 to 1.

1

When the test question was only used for binomial test with .50, the results were different. 29.8 37 40.9 35.8 43.2 24.5 .0 20.0 40.0 60.0 80.0 100.0 Uncertainty Certainty P ro b ab il it y o f su c cess 3-year-olds CL FB Self FB Other FB * * †

results showed that the children who heard the protagonist’s confident belief (-ci) were more likely to pass the task, p = .067 (two-tailed and hereafter). Twenty out of 54 children passed the question. In contrast, those in the uncertainty group with –keyss (-(u)l ke-ya) did not perform significantly differently from random responses, p = .54. Fourteen out of 47 children passed the question with uncertainty.

In order to examine whether the un/certainty expressions had a significant effect on the children’s understanding of beliefs, logistic regression was carried out with age and certainty (2X2). An interaction of age X certainty was also loaded controlling for vocabulary skills. That is, the dependent variable was performance on the change of location task and this logistic regression was explored to probe whether performance of the task was

significantly different with the use of the linguistic markers. The results showed that the model was not significant, Nagelkerke R2 = .02, χ2 (4, N = 101) = 1.3, p = .86. Taken together, the findings seem to indicate that the expressions of beliefs of either certainty (trend of

significance) or uncertainty (chance performance) might have a facilitative role in 3-year-olds’ understanding compared to performance of 3-year-olds showing below chance (Wellman et al., 2001). However, it seems that differences in the degrees of certainty may be subtle. The possible effects by exposure to the different degrees of certainty on beliefs will be reported below.

Effects of certainty on Self and Other FBs (UC)

As the main objective of the study was to investigate the role of the linguistic expressions on social understanding, performance on the Self and Other FB questions was analysed to explore possible carry over effects of the use of certainty markers in the change location tasks (where the markers were manipulated) to the unexpected contents test (where there was no manipulation of the markers). As shown in Figure 2.4, it seems that the

children’s performance on the unexpected contents task might be influenced by the previous task; thus, the performance on the Self and Other FBs might have been influenced by the experimenter-child interaction in a previous trial. That is, the performance on Self and Other FBs was examined in terms of the certainty used by the protagonist in the previous test. Seven children (one and six from 3.0- and 3.5-year-olds, respectively) were excluded from analyses for not attending the task by reason of absence from the second-week session. Hence, 97 children were included in analyses. Credits (1 = pass test and control question; 0 = fail one of the two questions or both) were given as in the change of location task.

Performance on each FB was analysed by binomial tests against chance (.25). First, the children with uncertainty showed performance at levels of above-chance, p = .03 and p

= .01 for the Self and Other FBs, respectively. Eighteen out of 44 children retrieved their past beliefs, while 19 out of 44 children predicted others’ action. In contrast to the findings of uncertainty, children with certainty performed at chance on the Self and Other FBs, p = .10, and p = 1.0, respectively. Nineteen and 13 out of 53 children respectively passed the Self and Other FBs after the exposure to certainty. It is apparent that the performance on the FBs, in particular the Other FB, might be affected by the use of the un/certainty markers along with different directions of the effects. Table 2.2 shows the changes between the change of location and Other FBs. As the change of location FB was to evaluate others’ beliefs, the comparison between Other FBs was carried out in Table 2.2. Again, the table revealed the differences in performance on the Other FB according to the levels of certainty in the previous experience: increase in the uncertainty group and decrease in the certainty group.

In summary, the finding showed that 3-year-old children’s performance to predict the protagonist’s behaviour might be dependent on the linguistic markers. The uncertainty

expression –keyss might function in weakening one’s attitude while the certainty marker –ci

Table 2.2

Contingency patterns of between the Change Location and Other FBs

Change Location FB

Uncertainty Certainty

Fail Pass Fail Pass

Other FB

Fail 17 8 25 15

Pass 13 6 8 5

Note. N = 97. FB: False belief

In order to probe further for the influences of the un/certainty markers, logistic regression on the respective FBs with age, certainty and an interaction of age X certainty were carried out, simultaneously taking into account verbal skills. There were differences for the FB questions. It was found that the overall model on the Self FB was not significant, Nagelkerke R2 = .03, χ2 (4, N = 97) = 1.84, p = .77. In contrast, the model with the variables explained the variance of the Other FB, Nagelkerke R2 = .16, χ2 (4, N = 97) = 12.0, p = .02. However, none of the individual variances had significant effects on the model. Thus, further analysis was carried out without an interaction of age X certainty and vocabulary. The results found that the overall model with age and certainty was significant, Nagelkerke R2 = .16, χ2 (2, N = 97) = 11.6, p = .003. As the inclusion of the age X certainty interaction in the model with age and certainty did not lead to a significant increase in the deviance explained, the model with the two main effects is shown in Table 2.3. The results indicated that age and certainty expressions were significantly associated with children’s understanding of others’ minds. The older 3-year-olds were four times more likely to predict the protagonist’s action than the younger children. The children who had heard the protagonist’s uncertainty were

more likely to understand others’ minds than those who had been exposed to his certainty. As mentioned above, the findings from logistic regression seem to suggest that children’ access to others’ epistemic states is influenced not only by the mental-state terms but also by the degrees of certainty.

Table 2.3

Summary of logistic regression analysis for predicting the Other FB

Variable B SE B Wald Δ Odds

Age 1.53 0.60 6.40* 4.60

Certainty -0.91 0.46 3.91* 0.40

Note. N = 97. FB: False belief. Nagelkerke R2 = .16, Model χ2 (2, N = 97) = 11.62, p = .003.

*

p < .05.