Misunderstood—or deliberately twisted—biological science leads to overheated rhetoric and bad policy. We like to think that science always illuminates. But the disturbing persistence of the concept of biological determinism—the false idea that human behavior is genetically fixed or inherently programmed and therefore is not susceptible to rapid change—shows that scientific research and concepts can be distorted to advance an inhumane and sometimes deadly political agenda. It was biological determinism that formed the basis of the theory of eugenics, which in turn led to the forced sterilization of “misfits” and the creation of Nazi death camps. In Killer Apes, Naked Apes, and Just Plain Nasty People, anthropologist Richard J. Perry delivers a scathing critique of determinism. Exploring the historical context and enduring popularity of the movement over the past century and a half, he debunks the facile and the reductionist thinking of so many popularizers of biological determinism while considering why biological explanations have resonated in ways that serve to justify deeply conservative points of view. Moving through time, from the prevalence of overt racism in the late nineteenth and early twentieth centuries to “human nature” arguments, from the rise of sociobiology in the 1970s to the current fixation on evolutionary psychology, the book argues that both history and cross-cultural studies amply demonstrate the human capacity for growth and self-determination. Clearly written, conversational, and rationally argued, this book promotes sound and careful research while skewering the bogus ideological assertions that have been used to justify colonialism, slavery, gender discrimination, neoliberal economic policies, and the general status quo.