Psychobiology of Competition: A Review of Men’s Endogenous Testosterone Dynamics

Abstract Competition is a defining feature of most living organisms. Among humans, the engagement in, and the associated outcomes of, competition (i.e., win or loss) can hold important consequences for survival, individual and group status, and mating-related opportunities. As such, considerable research efforts have been devoted to identifying and delineating the factors that influence human competitive decision-making. The steroid hormone testosterone, in particular, has been identified as one such factor, not only influencing competitive decision-making and behavior, but also responding flexibly to competitive cues and outcomes to then feedback to ongoing pursuits. Growing evidence suggests that the extent to which testosterone exerts its effects may depend on variables across a number of domains, such as individual preferences or dispositions, social cues, and other hormones. This chapter provides an overview of such competitive biopsychology with a focus on men’s testosterone dynamics. The authors provide a brief introduction to testosterone, and a summary of some of the key theoretical approaches to understanding testosterone dynamics in humans, followed by an overview of correlational and experimental studies that examine the independent and interactive effects of testosterone on competition and competition-related variables.