The literature on human attractiveness spans the sciences, social sciences, and humanities, and dates back at least to the time of Plato. Consequently, scholars across the disciplines have proposed and investigated a variety of ideas about what makes some people more or less attractive than others (e.g., Etcoff, 1999). Addressing this vast literature from an adaptationist perspective is well beyond the scope of this chapter. This chapter limits itself to (1) outlining an adaptationist perspective on physical attractiveness, (2) presenting the basic questions that this perspective leads us to ask,(3) reviewing some important empirical advances in the answering of these questions, and (4) highlighting research avenues calling for increased attention. I argue that human physical attractiveness assessment is generated by adaptations functioning to evaluate evolutionarily relevant cues to human social value across multiple domains of interaction (e.g., kin, mating, cooperation) and that evolutionary human life history theory and data from small-scale foraging societies are instrumental in generating predictions about these domains of social value and the cues associated with them.Multiple, converging lines of evidence are, useful to test whether a given phenotypic trait is an adaptation (e.g., Symons, 1989;Tooby & Cosmides, 1990). In the case of complex adaptations (e.g., immune systems, social exchange reasoning, or attractiveness-assessment psychologies), the most compelling case is made when there is evidence that: (1) the species in question recurrently faced a particular adaptive problem during recent evolutionary history, (2) the structure in question has a complex functional design that is so improbably well-suited to solving that adaptive problem that we are forced to reject pure chance as an alternative hypothesis, and (3) the organism in question shares with all normal conspecifics that design or a facultative developmental program that builds that design.