The Rational Animal

June 24, 2013
Did you just do something stupid? Don’t worry—psychology prof Kenrick (Sex, Murder, and the Meaning of Life) and “decision scientist” Griskevicius have some good news: even your worst decisions are rational—at least as far as evolution is concerned. The authors structure their argument around two key “insights”: “human decision making serves evolutionary goals,” and “human decision making is designed to achieve several very different evolutionary goals.” They assert that each person has seven “subselves” (the “self-protection,” “disease-avoidance,” “affiliation,” “status,” “mate-acquisition,” “mate-retention,” and the “kin-care subself”), each of which can be forced to react to environmental conditions in ways that are honed by evolutionary pressures to increase the chances of biological reproduction. Kenrick and Griskevicius present some interesting psychological studies to support their thesis, but their near-Panglossian view of human decision-making—one that could be marshaled to justify nearly any action according to an evolutionary standard that fails to take ethics into account—is distressing. They posit, for example, that overconfidence is favored by evolution to ensure that people “persist in the face of failure”—never mind the fact that this attitude “has been blamed for World War I, the Vietnam War, the war in Iraq.” Ultimately, their study is as readable as it is simplistic. 4 b&w illus.