In the 1960s, three books would capture Americans’ imagination about humankind’s evolutionary past. Konrad Lorenz’s On Aggression (1963), Robert Ardrey’s The Territorial Imperative (1966) and Desmond Morris’ The Naked Ape (1967) had important differences in emphasis and scientific rigour. Yet together they effectively introduced the notion of humans as “killer apes”, sweeping aside anthropological accounts that emphasised the endless adaptability of human cultures. Drawing on studies of ethology with a pronounced enthusiasm, Lorenz, Ardrey and Morris portrayed human behaviour – from tool use to social relations – as traceable to humans’ (specifically, men’s) biological impulse to be violent. Erika Lorraine Milam’s Creatures of Cain tells the story of the intellectual rise and fall of this evolutionary account of human aggression, and its popularisation within post-war US culture.
These three books – with their highly gendered and outré interpretation of human behaviour – would likely not have had the impact they did, Milam argues, if it were not for the cultural environment in which they circulated. Writing for popular audiences rather than scientists, the purveyors of the killer ape theory not only made use of Americans’ post-war demand for mass market paperbacks on scientific topics, but also benefited from the growing number of films, television shows and magazines, produced for niche audiences, in which provocative ideas could be aired. As controversial films such as Sam Peckinpah’s Straw Dogs and Stanley Kubrick’s A Clockwork Orange would attest, by the early 1970s many Americans were familiar with essentialist explanations of humans’ capacity for violence (even if they disputed them from a variety of political perspectives).
According to Milam, what sank the killer ape theory was not waning popular interest in biological theories of human nature, nor the progressivist critiques mounted by feminists, anti-racists and others. What did the trick was new evidence from primatologists that humans are hardly alone in their murderous behaviour. However, the intellectual foundation (some would say flaw) of the killer ape theory, its biological determinism, survived into the 1970s and beyond by taking new form within the genetic arguments of an emerging field, sociobiology. Sociobiological accounts of human nature appeared just as retrograde and unjustified to the scientists who had rallied against the killer ape theory. However, the battlefield changed in at least one significant way: while earlier controversies were hammered out in popular as well as scientific circles, both proponents and critics of sociobiology insisted on distinguishing between popular accounts of their ideas and professional academic arguments.
Milam’s book provides a nuanced intellectual history of the debates about human nature that emerged at the interface between anthropology, biology and ethology – debates that largely played out during the 1960s and 1970s in the wild and woolly area between US scientific and popular cultures. She follows a large cast of colourful personalities, setting their actions against a teeming backdrop of popular media, academic politics and social unrest. Since she sometimes seems agnostic about the bigger picture in her detailed reconstructions, this can sometimes make for slow going. Nonetheless, Creatures of Cain provides a multifaceted and original discussion of the curious life of the “killer ape” theory within American culture.
Marcia Holmes is a postdoctoral research associate at Birkbeck, University of London.
Creatures of Cain: The Hunt for Human Nature in Cold War America
By Erika Lorraine Milam
Princeton University Press 416pp, £24.00
ISBN 9780691181882
Published 8 January 2019
