At first, the researchers examined the sharing behavior of adults in the eight communities. Next, they looked at how children in the same communities shared rewards. The children were given a choice between a generous and a selfish distribution of reward. In the selfish distribution, the child received two rewards and another child – unknown to the first child – got nothing. In the generous distribution, the two children each received a reward.

Children under seven generally chose two rewards for themselves. Between the ages of eight and twelve, children in some of the communities increasingly opted for generosity. These children began to behave more like adults in their society. At the same age, children in all the communities began to respond more to social norms. They often chose the generous distribution, when they had previously viewed a video demonstrating that the generous distribution was “right.” After being shown a video indicating that “self-interest” was “right,” they were likely to behave selfishly.

The findings indicate that across cultures, children in middle childhood – i.e., between the ages of seven and ten – are particularly susceptible to culture-specific norms and their behavior becomes increasingly similar to adult behavior. These social learning processes are probably responsible for the differences in different sharing behavior in different communities. According to Dr. Kanngießer, “The study can help us to better understand how psychological developmental processes and cultural environments interact and generate diversity in cooperative behavior.”

The investigation was conducted in eight different groups in urban areas in Germany, the US, Argentina, and India and in rural communities in Ecuador, Vanuatu, Argentina, and Tanzania. Dr. Bailey House at the University of York (UK) led the project.