A Review of Sexual Selection and Human Evolution: How Mate Choice shaped Human Nature

The application of sexual selection theory to human behavior has been the greatest success story in evolutionary psychology, and one of the most fruitful and fascinating developments in the human sciences over the last two decades. Ironically, this development would have seemed absurd only twenty years ago. At that time, many biologists considered sexual selection through mate choice to be Darwin's least successful idea: if not outright wrong, it was at most a minor, uninteresting, even pathological evolutionary process. At that time, any "Darwinization" of the human sciences would have had to rely on natural selection theory, which bears much less directly on human social, sexual, and cultural behavior. Instead, something remarkable happened: sexual selection theory was revived over the last two decades through the combined efforts of researchers in theoretical population genetics, experimental behavioral biology, primatology, evolutionary anthropology, and evolutionary psychology. Today, although natural selection theory serves as the conceptual and rhetorical foundation for evolutionary psychology (see Tooby & Cosmides, 1990, 1992), sexual selection theory seems to guide more actual day-to-day research (see Buss, 1994; Ridley, 1993; Wright, 1994). This chapter reviews the current state of sexual selection theory, and outlines some applications to understanding human behavior. Sexual selection theory has been revived so recently that, while extraordinary opportunities exist for further research, many old misconceptions persist. These include the mistaken ideas that sexual selection:(1) always produces sex differences,(2) does not operate in monogamous species,(3) is weaker than natural selection, and(4) had nothing to do with the evolution of human intelligence, language, or creativity. One goal of this chapter will be to dispel some of these myths, and to bring evolutionary psychology up to date with respect to the biological literature on sexual selection. Sections 2 through 4 review the history and basic theory of sexual selection. Sections 5 and 6 contextualized human mate choice by covering sexual selection in primates and hominids. Sections 7 through 9 survey some possible roles of mate choice in shaping the human body, the human mind, and human culture. Finally, section 10 concludes with some academic and existential implications of applying sexual selection theory to understand htiinan nature.