Abstract: Over-imitation refers to the phenomenon that people imitate the actions purposely done by the model but irrelevant to the objective of the task. The underlying mechanism of children’s engagement in over-imitation has always been a heated topic in the field. Automatic Causal Encoding (ACE) theory suggested that the reason why children copy irrelevant actions is that they automatically code them as causally relevant to the expected outcomes. That is, they think the irrelevant actions are necessary to finish the task. By contrast, the “norm learning” explanation of over-imitation goes against ACE. Evidences are that when researchers asked the children why they copied the irrelevant actions, the children’s answers showed that they didn’t treat them as outcome-relevant. Otherwise, children gave out normative protecting words when others didn’t copy irrelevant actions. This result revealed that children might copy irrelevant actions out of obeying norms. However, it remains unclear whether children would copy irrelevant actions in the condition where they do not want to obey norms. Thus, the present study aims to fill the gap by assessing the children’s reaction when the motivation of obeying norms is low. Ninety-four 4- to 6-year-old children participated in the current research. Simple materials and actions were used to assure that children can distinguish between relevant and irrelevant actions. At first, children were asked to watch the experimenter perform the irrelevant action (lock the box) followed by the relevant action (lift up the lip and take out the sticker). Then, they were allowed to get a sticker inside a box almost the same as the one the experimenter used. Children were randomly assigned into one of the two experimental conditions. In the high-motivation condition, coping irrelevant actions led to successful reaching for the sticker. Whereas in the low-motivation condition, copying irrelevant actions would get the box locked, thus children would fail in getting the stickers. Therefore, children would not want to obey the norm of copying all the actions in the low-motivation condition. A Chi-square test of independence revealed that children are significantly more likely to over-imitate irrelevant actions in the high-motivation condition than in low-motivation condition (χ^2(2, N = 94) = 26.38，p < 0.001, Cramer’s V = 0.53), with no age differences having been detached (High-motivation condition: χ^2(2, N = 45) = 4.89，p = 0.087，Cramer’s V = 0.33; low-motivation condition: χ^2(4, N = 49) = 5.60，p = 0.231, Cramer’s V = 0.24). Especially, in the low-motivation condition, only 28.60% children copied irrelevant actions (the “over-imitators”), whereas 44.90% omitted them (“selective imitators”), and 26.50% were “hesitators” who stopped copying in the halfway and got the sticker successfully. On the contrary, in the high-motivation condition, 77.80% children copied the irrelevant actions, and only 22.20% children omitted them. It is obvious that children in the high-motivation condition showed strong tendency of copying irrelevant actions, but when they confronted with the low-motivation condition, they turned out to omit irrelevant actions and get the stickers. The current study suggested that children in the experiment have a tendency of obeying norms, and that is why they copied irrelevant actions in high-motivation conditions. Children were able to identify the irrelevant actions and omit them in the low-motivation condition when copying irrelevant actions would keep the expected outcomes away, so were the children in the high-motivation condition. The reason why they still copied these redundant actions is that they hoped to behave normatively alike to the experimenter. There is a trade-off between norms and outcomes when children were going to imitate.

Key words: over-imitation, selective imitation, norm learning

摘要： 模仿非任务相关动作的行为被称为过度模仿。研究以94名4-6岁儿童为被试，通过操纵无关动作与结果之间的关系，考察了儿童遵守规范的动机对过度模仿的影响。结果发现，当遵守规范导致不能得到想要的结果时，儿童没有表现出明显的过度模仿；而当遵守规范与得到结果不冲突时，儿童过度模仿的比例显著增加。这些结果说明遵守规范的动机影响儿童的过度模行为，当遵守规范的动机降低时，过度模仿行为减少。

关键词: 过度模仿, 选择模仿, 规范