Nadine Weidman, Killer Instinct: The Popular Science of Human Nature in Twentieth-Century America, Cambridge: Harvard University Press, 2021, ISBN 9780674983472, 368 pp.

Killer Instinct traces how scientists and science writers constructed, popularized, and debated human nature from the 1930s to the early 1980s.Over these 50-some years two rival conceptions of human nature, one as inherently aggressive and violent, the other as yearning for love and cooperation, competed for public acceptance and political influence and were in turn politicized and polemicized.The first arc in Nadine Weidman's account spans the first five chapters and presents different conceptions of human nature, explains their development, and then traces the dynamics of the debates surrounding them in published materials, both popular and scientific.Popular writing and scientific engagement with the public were critical aspects of these debates.Konrad Lorenz, Robert Ardrey, Ashley Montagu-all of them were aware of their status inside, outside, or on the periphery of science and how that status could be used to attract and persuade audiences.Weidman portrays Lorenz as a professional scientist encouraging amateurs to engage with animal behavior through the power of observation, Ardrey is depicted as an amateur proudly proclaiming that his outsider status conferred precisely the clarity that science was lacking, while Montagu is shown as playing an uneasy role as the public face of anthropology without an academic home in the discipline for much of his career.By not limiting her analysis to scientific publications, Weidman draws a rich picture of how the human nature debate played out in the public sphere.Weidman offers exceptionally clear and lucid explanations of the scientific ideas and background motivations of her actors, such as Lorenzian instinct theory, but her analysis truly shines when she looks beyond individual scientists and shows their interaction within and across the pre-conceived camps of the debate.This focus on interactions pays off in big ways-showing that the theories and ideas of her actors did not develop in isolation-and in small: we learn that Montagu and Ardrey commiserated about their role as non-academic science popularizers while engaging in a heated public debate about the nature of aggression, for example.The first chapter