Philosophers and therapists have long theorised about how psychological mechanisms for love, jealousy, anxiety, depression and many other human characteristics may have evolved over millions of years. In the dawn of the new insights on evolution, provided by Darwin's theories of natural selection, Freud, Jung and Klein sought to identify and understand human motives, emotions and information processing as functions deeply-rooted in our evolved history. Despite this promising start and major developments in modern evolutionary psychology, anthropology and sociobiology, the last fifty years has...