Warneken, F., & Tomasello, M. (2013). The emergence of contingent reciprocity in young children. Journal of Experimental Child Psychology, 116(2), 338–350.
This is another crucial study by Tomasello and his team. The researchers designed games to be played individually by the toddlers participating in the study. The child and the researcher would play in parallel, side by side. At some point the child would need more resources to continue playing and these would have to be provided by the researcher; later the researcher would lack resources and the child would have the opportunity to either help the researcher or defect. As the authors put it: “we gave 2- and 3-year-old children the opportunity to either help or share with a partner after that partner either had or had not previously helped or shared with the children. Previous helping did not influence children’s helping. In contrast, previous sharing by the partner led to greater sharing in 3-year-olds but not in 2-year-olds.”
These results do not support theories claiming either that reciprocity is fundamental to the origins of children’s prosocial behavior or that it is irrelevant. Instead, they support an account in which children’s prosocial behavior emerges spontaneously but is later mediated by reciprocity.
It is not until 3.5 years of age that children modulate their sharing contingent on the partner’s antecedent behavior. Children first develop prosocial tendencies (already present in babies or young toddlers) and later those tendencies become mediated by reciprocal strategies. Helping and sharing emerge before children begin to worry about direct reciprocity. Later in development, they seem to become more sensitive to reciprocity, adjusting their prosocial behavior accordingly.