分享行为是常见的一种重要的亲社会行为，对分享行为的理解能够帮助我们更好地认识亲社会表现。分享行为背后的一种重要机制就是互惠，尽管以往研究关注互动情境下，幼儿作为响应者的分享表现如何受到互惠规范的引导，但是研究结论并不一致，同时也较少从提议者角度探讨个体基于互惠预期产生的分享行为。
为了明确互惠规范对响应者分享行为的引导，也为了探究幼儿作为提议者是否会基于互惠预期主动分享，本研究分别从响应者和提议者两个角度，同时对幼儿的分享表现进行探讨。本论文共包含两项研究，研究一以 3–5 岁幼儿为被试，采用独裁者博弈任务，考察幼儿作为响应者的时候，其分享表现如何受到同伴先前分享行为的影响，关注互惠对幼儿分享反馈的规范作用。研究二以 4–5 岁幼儿为被试，采用独裁者博弈任务和简版独裁者博弈任务，考察幼儿作为提议者的时候，其分享表现如何受到同伴随后潜在的分享反馈的影响，关注互惠预期对幼儿分享行为的作用。
本研究的主要结果有：
（1）作为响应者，3 岁幼儿就能够根据同伴之前是否分享调整自己随后的分享行为，同伴先前的分享能够引发他们随后更高的分享量。甚至，同伴先前分享物品的数量多少，和分享物品的价值高低也会影响幼儿随后的分享表现，当同伴分享的物品数量较多或价值较高时，幼儿随后的分享水平相应更高。另外，研究发现，在重复互动过程中，同伴的分享反馈不仅受到同伴当下分享行为的影响，同时也受到同伴之前分享表现的影响。这一研究结果明确了幼儿在单轮互动中会以“一报还一报”的方式关联同伴当下的分享，而在重复互动中幼儿的分享表现即关联同伴当下的分享表现，也关联同伴之前的分享表现。
（2）作为提议者，幼儿从 5 岁开始能够基于互惠预期进行分享，面对有互惠机会的同伴，他们表现出更高的分享水平。尤其当同伴有可能通过随后的反馈分享高价值的物品给幼儿时，幼儿会主动分享更多的物品。但是，结果并没有发现，当同伴随后有可能返还更高数量的物品时，5岁幼儿会作为提议者分享更多物品。
结论：在幼儿阶段，对互惠规范的遵循和对互惠的预期能够分别引导个体作为响应者和提议者时的分享表现。从发展顺序上看，幼儿作为响应者时互惠规范对其分享行为的指导作用早于作为提议者时互惠预期对其分享行为的指导。这一发展上的不同步表明，不同角色做出分享行为有不同的心理过程，可能基于不同的心理机制。

Sharing is a type of prosocial behavior, which is widespread in social society. The exploration of sharing behavior is critical for us to understand prosocial behavior. Reciprocity is an important mechanism underlying sharing, which  can explain sharing behavior in an interactive situation. Although previous researches have investigated preschoolers’ sharing when they play as a recipient, there is no consistent conclusion about when their sharing behavior follows reciprocity rule. At the same time,  we know little about whether  preschoolers’ sharing based on the anticipation of reciprocity, when they playing as an actor.  
To fill this gap, the current study investigated preschoolers’ sharing behavior both from a recipient’s perspective  and an actor’s perspective. The current study had two aims. One was to investigate when recipients’ sharing behavior would follow the reciprocity rule. The other one was to investigate whether actors would share based on anticipated reciprocity. There were two studies in the current work. The first study adopted the dictator game, and explored recipients’ feedback towards their partner’s previous sharing in children aged 3 to 5. The second study adopted the dictator game and the mini-dictator game. It explored whether actors’  sharing behavior was influenced by their partner’s potential reciprocity in children aged 4 to 5. The main findings in the current study were as following:
(1) By 3 years of age, children could adjust their subsequent sharing behavior according to the partner's prior sharing, when playing as a recipient. Specifically, they would share more if their partner shared with them previously. Moreover, the more items their partner shared, and also the higher value their partner shared, the more children would repay. In addition, the study found that in a repeated interaction, children’s sharing was not only influenced by their partner’s immediately prior sharing, but also by their partner’s previous sharing behavior during the whole interaction. It demonstrated that preschoolers’ feedback would follow a tit-for-tat way in an one-shot interaction. While in a repeated interaction, preschoolers’  feedback was related both with the partner’s immediately prior sharing and with the partner’s previous sharing behavior.
(2) When playing as an actor, children from the age of 5 were able to share,  based on anticipated reciprocity. Children shared more items if their partner had an opportunity to reciprocate, especially when the partner held some items with higher value. Yet, we did not found children would  share more if their partner had the possibility to repay more items rather than desirable items. These results indicate that preschoolers’ sharing behavior  is guided by reciprocity rule no matter they play as a recipient or an actor. What’s more, the guidance of reciprocity for recipients developed earlier than its guidance for actors. These different developmental trajectories suggest that sharing behavior in different parts is based on  different  mental processes or different psychological mechanisms.