Book Reviews

Theories of human nature have a long but troubled history. Hobbes was certain that everyone is born, and always remains, self-interested; he had no good reason to think so, no evidence that individuals only seek their own advantage, and yet he relied on his theory to explain why individuals must bind themselves to a monarch in order to be secure. According to Dupré, recent theories of human nature are no different—they tell us that actions are done to maximize some single magnitude, personal utility, or fitness; and while there is no evidence that human behavior fits these economic or evolutionary models, they are used to support a political agenda, much as Hobbes used his model of humankind’s selfishness to support the reign of kings. Dupré aims to explain the reasons why we are tempted to think, as Hobbes did, that one model of human motivation fits all, and why recent evolutionary and economic models of human behavior should be resisted. Chapter 1 introduces the book’s themes: (i) that dynamically evolving systems, like the brain, cannot be understood in terms of the interactions of the intrinsic properties of their constituent parts; (ii) that the intrinsic properties of the brain affect behavior differently in different social contexts, and, as a result, questions about human behavior can only be answered by describing some feature of the social context in which the behavior occurs; (iii) that a complex domain cannot be understood from a single perspective, theory, or model, or methodology; (iv) that models of human motivation should be supported by a body of empirical evidence before they are used to explain human behavior; and (v) that many evolutionary psychologists and economists tend to ignore (i)– (iv) because they are committed to methodological reductionism, and mistakenly believe both that nature is unified and that science has a single method. Chapter 2 shows how evolutionary psychology ignores (i) and (ii). Evolutionary explanations of human behavior rely on three questionable assumptions: (a) the brain consists of modules; (b) each module controls a domain of behavior, e.g. parenting or mating; and (c) each module was selected over others during the course of humankind’s evolutionary history as a result of the reproductive advantage conferred on some human ancestors. Dupré argues that too little is known about how the brain works, or the course of evolutionary history, to even begin to assess these assumptions. In addition, the interactions between the capacities of our brains and the social environment in which the capacities are exercised are too complex to speak either of a module or gene for a capacity. Moreover, the causal processes that lead to changes in the frequency of a gene in a population, i.e. evolution, are numerous, and natural selection, at any level—the gene, individual, or group—is but one. Chapter 3 shows how (a)–(c) govern the way evolutionary psychologists explain interspecific or cross-cultural differences in male/female behavior. The two sexes, they speculate, have different utility functions (preferences), and the differences are due to different selection pressures on the evolution of male/female brains. According to Dupré, there is little evidence that the behavioral differences cited by evolutionary psychologists are cross-cultural—let alone interspecific—and even less evidence of any male/female differences in selection pressures in some distant past. Evolutionary explanations of behavioral differences between human subpopulations, Dupré argues, violate (iv), the admonishment to respect the available evidence. In Chapter 4, Dupré explains why, in the absence of empirical evidence, a psychologist would favor an evolutionary explanation of differences in male/female behavior. He explains how these explanations favor a conservative political interest, but he does not maintain, as other critics of evolutionary psychology (e.g. Richard Lewontin) have, that the psychologists favor the explanations because the explanations favor those inter-