The Influence Of Being Only-child Or Not To The Cognitive Mechanism Of Perspective-taking

Perspective taking, namely "seeing the world through others’eyes", includes the meaning of space and the metaphor of social aspects. The previous research (Shelton, 2012) has shown that in " Three Buildings Test", one experimental paradigm adapted from Piaget’s well-known "Three mountain test", when the target is a potential agent, the participants’performance in the Three Buildings Test is related to their social skills. But previous studies focused on discussing the characteristic of the "targets", lacking investigations on perspective-taker, namely the group differences of subjects, this research attempts to have a try in this respect. This study focuses on these two groups, the only child and child with sibling. We want to know their developmental differences on the ability of perspective taking, including the relation with social skills, and the strategy behind the differences.In Experiment 1, we copied the experimental paradigm of Shelton(2012),96 subjects (47 one-child,49 child with sibling) participated in the "three Buildings test", then filled out the questionnaire of autism traits. The Results showed that the two groups had no significant differences in the performances of the two tests. But the correlation between these tasks is of obvious difference:for the group of child with sibling, their performance on perspective taking was significantly associated with social skills, while the one-child group had no such correlation. Furthermore, after subdividing the group of child with sibling, we found that such difference is more prominent between "the older sibling" group and "the younger sibling" group, the same pattern also exists in the "one-child before the age of 5 " group and "child with sibling before 5" group, namely the correlation between the performance of perspective taking and the social skills appears in the "the younger sibling" group and "child with sibling before 5" group, whereas no such relationship was observed in "the older sibling" group and the " one-child before the age of 5 " group.In Experiment 2, subjects were divided into four groups (21 people in each group):the one-child group, the "home eldest sibling and A1-A2≥5" group (Al refers to the age of the home eldest sibling, A2 refers to the age of the second child in the family), the "home eldest sibling and A1-A2< 5" group, and "the younger sibling" group. The results showed that the correlation between the performance of perspective taking and the social skills appears in the last two groups, but not in the first two. Thus it proved that the state of being the only-child or child with sibling during the crucial period is the most important factor impacting the relation between the ability of perspective taking and social skills, rather than ranking or the simple label as the only-child or child with sibling. That is to say, dividing the subjects into the " one-child before the age of 5 " group and the " child with sibling before 5" group is closer to their essential distinguish, than a simple distinction as only-child or child with sibling.In Experiment 3, we tried to study the possible reason behind these differences, the strategy. We divided participants into three groups:the one-child groups, the " one-child before the age of 5 " group (the group 2 in Experiment 2), and the " child with sibling before 5" group (the combination of group 3 and 4 in Experiment 2).All subjects completed the "Three building test" and two types of mental rotation tasks-"Array-rotation" and " self-rotation" in order. The results showed that there were no significant differences (reaction time and accuracy) in the three groups on three tasks. But as to the correlation among tasks’performance:the performance of perspective taking is significantly associated to "Array-rotation" in all three groups, which indicates that the array-rotation, this special type of mental rotation, could be a foundation of perspective taking task.But it is important to note that another special association, that is, the performance of perspective taking is significantly associated to "self-rotation", was only found in the child-with-sibling groups (group 2, and 3), but not in the only-child group. It means when completing the perspective taking task, "child with sibling" group has more "self-rotation" strategy than only-child. But this difference in strategy seems only distinguish only-child and child with sibling, and failed to distinguish between " one-child before the age of 5 " group and the " child with sibling before 5" group.This reveals another interesting phenomenon, namely the relation between perspective taking and social skills is not correspondence with the relation to their strategy. In the discussion, some explanations are given.In conclusion, this study found that during the crucial period of developing perspective taking, the sibling composition in their family, whether being accompany with brothers and sisters) makes some difference in their cognitive mechanism——more siblings, more interaction in the ability of perspective taking and social factors.