Choose the generous reward

Cooperative behaviors, which differ from one country to another, from one community to another, can make the world an interesting — though sometimes challenging place — to live. But, these differences in behavior may be based on a deeper similarity, a shared window when children across societies begin adopting the cooperative social norms of the adults around them.

Researchers Bailey House of the University of York in the United Kingdom and Joan Silk of Arizona State University led an international team of collaborators working in eight societies around the globe in a cross-cultural study of cooperative behavior in children and adults. The participating groups differ widely in the size of their communities, their subsistence strategies and locations — from urban communities in Germany, the U.S., Argentina and India, to rural communities in Ecuador, Vanuatu and Argentina, and hunter-gathers in Tanzania. The results of this research are published this week in Nature Human Behavior.

House is an assistant professor of psychology and a former postdoctoral researcher at ASU. Silk is a research affiliate with the Institute of Human Origins and professor in the School of Human Evolution and Social Change.

The researchers used a simplified version of the “Dictator Game” for the experiments. In the Dictator Game, adults and children ages 4 to 13 are given a choice between two options — a “generous” option provides one reward (some kind of desirable food item) for the subject and one reward for a peer. The “selfish” option provides two rewards for the subject and none for the peer.

Earlier research found that there is a wide variety of responses across cultures to this game, so the researchers were not surprised to find cultural variation in the responses of adults in the experiments. But how can we know if this cultural variation is due to differences in social norms?

To determine this, after adult participants chose the generous or selfish option, the researchers showed them two videos — a generous video that said the generous option was “right and good to choose,” and a selfish video that said the selfish option was “right and good to choose.” The researchers then asked the participants which of the videos they believed was “most correct” and found that people were more likely to choose the generous option in communities where most people believed that the generous video was “most correct.”

“If social norms matter,” said House and Silk in an accompanying blog for Nature Human Behavior, “then people’s behavior in the Dictator Game should be at least partly influenced by the beliefs of other people within their own societies. And that is what we found.”

In children, societal variation in generous choices did not emerge until children reached middle childhood (around 8 to 10 years of age), as children’s choices began to converge on the behavior of adults within their own societies. At about the same age, children in all societies also began to more strongly respond to social norms: They shared more when they were told that the generous option was “right,” and they shared less when they were told that the selfish option was “right.” This suggests that children, like adults, are influenced by social norms — and that this influence increases substantially during middle childhood.

"Cross-cultural studies like this one illuminate our similarities and our differences," said Silk. "The psychological processes that enable children to learn how to be good seem to be the same across cultures. But what it means to be a good person can vary. We are prepared to learn how to be good."

“One of the implications of the study,” said House, “is that we should start to pay attention not just to what children know but why they start to follow social norms. The next step is to pose the question of what is happening in a child’s development between the ages of 8 and 12 that makes them more responsive to social norms around them. The goal of the work is to better understand how culture and psychological maturation work together to produce human diversity in cooperation and other behaviors.”