Chapter 8 provides an overview of evolutionary approaches to personality. The authors begin by introducing the key concepts of evolution by natural selection and evolution by sexual selection. They then discuss the role of genes in the context of inclusive fitness theory, noting that evolution occurs by differential gene reproduction.

Next, the authors identify and discuss the three key products of the evolutionary process: Adaptations, by-products of adaptations, and noise or random variation. Adaptations are inherited solutions to the survival and reproductive problems faced by humans throughout human evolutionary history, and are the primary focus of modern evolutionary scientists, including evolutionary personality psychologists.

The authors turn next to the premises of evolutionary psychology, which include presumptions that the adaptations of the mind are likely to be domain-specific, numerous, and functional—that is, that they have special function or solve specific adaptive problems.

The authors then discuss the nature by which evolutionary hypotheses are tested empirically, distinguishing between general evolutionary theory, middle-level theories, and the specific hypotheses and derivative predictions that are the typical focus of empirical testing. The authors then discuss and provide examples of three levels of evolutionary psychological analysis—the level of human nature, or species-typical adaptations, sex differences, and individual differences.

The authors conclude with a discussion of several limitations of evolutionary psychology, including the fact that modern conditions are sometimes different from ancestral conditions, and so what was adaptive in the past might not be adaptive in the present.