Although many studies have concluded that males are more aggressive than females in a variety of situations, significant variation exists among individuals in their willingness to respond to provocation with aggressive behavior. The pervasiveness of the sex role stereotyping of aggressiveness as a masculine trait and passivity as a feminine trait suggests that self-rated sex roles, as measured by the Bem Sex Role Inventory (BSRI), may predict different response tendencies in individuals confronted by an interpersonal provocation. Masculine, feminine, and androgynous subjects (N=60) of both sexes were selected from their BSRI scores and placed in a situation that ostensibly demanded cooperation with a same-sex confederate on a physically tiring task. Provocation consisted of the confederate's selfishness in maximizing personal gain by working harder on individual reward trials and less on the subject's trials. Gender differences were found in the manner in which subjects responded to this provocation. Differences also emerged within each sex along the lines of self-rated sex role; individuals of the same sex role but differing in biological sex had substantially different responses. (NRB)