People cooperate to enjoy mutually satisfying relationships, create productive organizations, maintain societal institutions, and conserve valuable resources. Yet, all-too-often people fail to cooperate. The Amsterdam Cooperation Lab (ACL) is composed of behavioral and social scientists interested in understanding why, when, and how humans cooperate. We apply experimental methods, field methods, and meta-analysis, to test theory about human cooperation. We often study cooperation in situations when cooperation is difficult to achieve, such as in social dilemmas. Social dilemmas occur when each person has a tempting option to not cooperate and benefit from the cooperation of others. However, if everyone decided not to cooperate, then everyone receives a worse outcome compared to if everyone decided to cooperate. Social dilemmas can occur in almost any domain in our social lives, such as in close relationships, coworkers in an organization, members of a society, and interactions between groups. Here you can discover more about our research projects, the people working in the lab, and recent publications.