What cognitive abilities enable cooperative behavior? Why do we feel committed to our partners, friends, and collaborators? What motivates us to help others? In the Cooperative Minds Lab, we conduct behavioral experiments with young children, in which we aim to understand how cognitive, societal, and cultural factors shape the development of human cooperation. In addition, we explore potential pitfalls of our cooperative psychology and ask if our prosocial motives can sometimes lead us astray. Do we favor previous benefactors when we should be impartial, turn a blind eye to a friend’s transgression instead of defending a rule we believe in, or cut corners to benefit our group at the expense of the collective? By answering these questions, we hope to shed light on whether human cooperative cognition, rightly championed as responsible for humanity’s greatest accomplishments, may also be implicated in some of our less favorable attributes. Finally, we investigate the psychological mechanisms that support cooperation in chimpanzees, human’s closest evolutionary relatives. Together, our research aims to contribute to a better understanding of uniquely human sociality.