Abstract
Physical competition is widespread in human societies. Because performance in competitive sports can signal phenotypic quality and fighting ability, high level performance, especially on the part of men, is likely to be attractive to the opposite sex. We investigated the relationship between involvement in competitive sport and self-reported numbers of sexual partners. Both male and female students who compete in sports reported significantly higher numbers of partners than other students, and within the athletes, higher levels of performance predicted more partners. Among men, body mass index (BMI) and educational level also had significant effects. We discuss possible implications for the evolution of competitive sport, ritual fighting behavior, and the persistence of left-handedness.