Why do humans cooperate?

Cooperation can be mutually beneficial, but comes with the risk of being exploited by freeriders. How do people navigate the decisions of when, with whom, and how much to cooperate? My research takes an evolutionary and cultural approach to these problems, as I try to explain universal derived features of human cooperation, as well as variation within and between populations. I primarily conduct research in the field with the Hadza hunter-gatherers, using methods drawn from experimental economics, social psychology, and anthropology. 

I also conduct research in laboratory settings on a number of other topics, including moral judgment, social cognition, and economic decision-making.