From prosociality to reciprocity: A developmental shift in children's friendship concept.

Friendships are fundamental to children's social and cognitive development. Previous research has shown that children understand the importance of various aspects of friendship, including prosocial behaviors. However, it is an open question whether children believe that prosocial behaviors should be reciprocated between friends. Across two experiments with 4- to 8-year-old participants (total N = 236), we examined how children weighed the importance of reciprocity and prosociality in friendship formation. Children were asked to predict which of two pairs-one in which both individuals provided prosocial behaviors (the reciprocal pair) and one in which only one individual provided prosocial behaviors (the nonreciprocal pair)-would become better friends. We found that younger children consistently favored the nonreciprocal pair, but with age, children became more likely to choose the reciprocal pair. By age 7, children reliably preferred the reciprocal pair, suggesting that they recognize the importance of reciprocity above and beyond prosociality in friendship formation. These findings shed new light on the theoretical debate on the role of reciprocity in friendship, and suggest that reciprocity may be an important component of children's mature concept of friendship. (PsycInfo Database Record (c) 2026 APA, all rights reserved).