Demonic Males: Apes and the Origins of Human Violence
 It considers violence in chimpanzees and its relationship to violence in human beings, while also reflecting on the more peace-loving bonobo. It also considers the relation of gender to violence, noting that in humans it is males which are violent, while in other animals e.g. hyenas it is the female that is more violent; according to Philip Regal the book is partly an attack on the deconstructivist feminist theory that male violence is a purely social construct. Regal also considers the book to be "a broadside against the old utopian dreams of Atlantis, Eden, Elysium, a Golden Age, Romantic paintings, and the late Margaret Mead" which imagined human beings as naturally peaceful.