Research professor of psychology and neuroscience at Boston College, Peter Gray has spent the past 30 years studying the role of play in human evolution and development — particularly how children educate themselves through self-directed play and exploration when free to do so. His evolutionary approach to psychology informs his influential textbook Psychology (Macmillan), now in its 8th edition. His book Free to Learn, translated into 18 languages, makes the case that unleashing the instinct to play is the surest path to raising capable, self-reliant, happy children. He authors the Freedom to Learn blog for Psychology Today and the Play Makes Us Human Substack, and is a co-founder of Let Grow.