Peter Gray's research interests broadly span the evolution of human reproductive behavior, comparative primate behavior and behavioral and reproductive endocrinology.
Gray has authored articles and book chapters on topics including male testosterone and social behavior, age-related changes in physiology and behavior, evolution and variation in fathering, links between sexuality and parenting, body image, and human-pet relationships. Several of these recent publications -- such as on dating and sexual activity of single parents, and the role of pet dogs and cats in human dating and courtship -- have attracted wider media attention.
He is the co-author of Evolution and Human Sexual Behavior (Harvard University Press, 2013), a comprehensive, one-volume survey of the evolutionary science of human sexual behavior and why sexuality has remained a core fascination of human beings throughout time and across cultures. He is the co-author of Fatherhood: Evolution and Human Paternal Behavior (Harvard University Press, 2010), a book that integrates evolutionary, comparative, cross-cultural, and neuroendocrine aspects of fatherhood, with attention given to the impacts of fatherhood on men's physiology, sexuality, and health, among other areas. He has also co-edited Endocrinology of Social Relationships (Harvard University Press, 2009), a volume that considers evolutionary, comparative, and endocrine aspects of pair bonding, parent-child and other relationships.