As the scope of the contributions in this volume illustrates, the evolutionary approach has the potential to inform many of the content areas of interest to social psychologists, such as relationships (Fletcher, Simpson, & Boyes, this volume), cooperation (Van Vugt & Van Lange, this volume), and emotions (Keltner, Haidt, & Shiota, this volume). However, in addition to informing hypotheses about the content of human social cognition, the evolutionary approach also brings to the fore an important idea about the structure of cognition: that information-processing systems sculpted by natural selection are likely to show functional specificity. Because information-processing systems gain in power by restricting the domain of problem space on which they operate, natural selection favors functionally specific mechanisms over mechanisms with a broader domain of application (Tooby & Cosmides, 1992). This leads to a cognitive architecture that consists of a large number of specialized information-processing systems each with its own narrowly defined function as opposed to a small number of very general systems that are responsible for performing a wide range of functions (Rozin, 1976; Symons, 1979).