Tomasello, a professor of psychology and neuroscience at Duke University, has applied a comparative and developmental approach toward seeking answers. His studies on the psychological processes of social cognition, social learning, cooperation, and communication shed light on human uniqueness as well as on the cognitive abilities of our closest ape relatives. Tomasello, who is emeritus director of the Max Planck Institute for Evolutionary Anthropology, was elected to the National Academy of Sciences in 2017. His Inaugural Article (IA) explores why human infants and great apes are capable of passing some tests of social cognition, whereas only older children can pass others.