Peter Gray Peter Gray, Ph.D., research professor at Boston College, is author of Free to Learn (Basic Books, 2013) and Psychology (Worth Publishers, a college textbook now in its 7th edition). He has conducted and published research in comparative, evolutionary, developmental, and educational psychology. He did his undergraduate study at Columbia University and earned a Ph.D. in biological sciences at Rockefeller University. His current research and writing focus primarily on children's natural ways of learning and the life-long value of play. His own play includes not only his research and writing, but also long distance bicycling, kayaking, back-woods skiing, and vegetable gardening.