Creatures of Cain: The Hunt for Human Nature in Cold War America

Now available from Princeton University Press!


“The Hunt for Human Nature,” (08 November 2018): link.

Q & A on Princeton University Press Blog (15 January 2019): link.

PODCAST: Q & A with Erika Milam and Valerie Thompson about Creatures of Cain, Science Books, et al. (25 January 2019): link.

PODCAST: Time to Eat the Dogs with Michael Robinson (8 April 2019): link.

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After World War II, the question of how to define a universal human nature took on new urgency. Creatures of Cain charts the rise and precipitous fall in Cold War America of a theory that attributed man’s evolutionary success to his unique capacity for murder.

Drawing on a wealth of archival materials and in-depth interviews, Erika Lorraine Milam reveals how the scientists who advanced this “killer ape” theory capitalized on an expanding postwar market in intellectual paperbacks and widespread faith in the power of science to solve humanity’s problems, even to answer the most fundamental questions of human identity. The killer ape theory spread quickly from colloquial science publications to late-night television, classrooms, political debates, and Hollywood films. Behind the scenes, however, scientists were sharply divided, their disagreements centering squarely on questions of race and gender. Then, in the 1970s, the theory unraveled altogether when primatologists discovered that chimpanzees also kill members of their own species. While the discovery brought an end to definitions of human exceptionalism delineated by violence, Milam shows how some evolutionists began to argue for a shared chimpanzee-human history of aggression even as other scientists discredited such theories as sloppy popularizations.

A wide-ranging account of a compelling episode in American science, Creatures of Cain argues that the legacy of the killer ape persists today in the conviction that science can resolve the essential dilemmas of human nature.


Advance praise: 

“Erika Lorraine Milam’s magisterial account of the sciences of human nature in Cold War America weaves together ideas and politics, vivid personalities and scientific evidence, mass-media hype and arduous fieldwork, educational reform and daring movies, all against the background of the tumultuous decades between Sputnik and Watergate. It is a very human story about trying to understand what it means to be human. It is also a whopping good read.” — Lorraine Daston, director, Max Planck Institute for the History of Science

“In this brilliantly creative and eye-opening book, Erika Lorraine Milam shows how the Cold War radically transformed popular and scientific attitudes towards human nature. Though eugenics went out of fashion after World War II, new theories of innate human aggression came to rationalize and simplify a violent world—a development with wide-ranging ramifications at the time as well as disturbing legacies and parallels today. Milam teaches once again that appeals to nature always turn out to be politics by other means.” — Samuel Moyn, Yale University

“Milam provides a new understanding of how scientists and their publics negotiate knowledge production on topics of significant political meaning. Creatures of Cain is an important book, especially in our current political environment.” — Jamie Cohen-Cole, author of The Open Mind: Cold War Politics and the Sciences of Human Nature

“Milam’s fine book explores the renewed fascination in postwar America with the roots of human aggression and so makes an important contribution not only to the history of science but also to our understanding of the broader American postwar context.” — Hunter Heyck, author of Herbert A. Simon: The Bounds of Reason in Modern America and Age of System

“Why have biologists come to characterize human behavior as innately violent? In this exciting book exploring the cultural impact of science, Erika Lorraine Milam shows how postwar authors increasingly came to regard human beings as little more than cavemen with a territorial imperative—and reveals momentous shifts in twentieth-century American culture.” — Janet Browne, author of Charles Darwin: A Biography and editor of The Quotable Darwin


“By focusing on a genre [Milam] calls “colloquial science” — books and articles about scientific theories written in accessible language and meant to be read by a broad audience — she is able to show how these debates spilled over from scientific journals or seminar rooms into popular discourse, and the arts and politics, becoming tools for collective self-interpretation.” —Melinda Baldwin, Los Angeles Review of Books (17 June 2019).

“A multifaceted and original discussion of the curious life of the 'killer ape' theory within American culture.” —Marcia Holmes, Times Higher Education (14 March 2019).


Research for this book was supported by a Scholar’s Award from the Science, Technology & Society program at the National Science Foundation (SES-1057586), Princeton University, and the University of Maryland. The Max Planck Institute for the History of Science, Berlin provided a year of blissful writing.