Peter Gray, research professor of psychology at Boston College, has conducted and published research in neuroendocrinology, developmental psychology, anthropology, and education.  He is author of an internationally acclaimed introductory psychology textbook, which views all of psychology from an evolutionary perspective.  Much of his research focuses on the role of play in human evolution and how children educate themselves, through play and exploration.  He has expanded on these ideas in his book, Free to Learn. He also authors a regular blog called Freedom to Learn, for Psychology Today magazine. and a Substack series entitled Play Makes Us Human, and is a co-founder of the nonprofits Alliance for Self-Directed Education and Let Grow, both of which work for greater freedom and self-direction for children.