endogenous testosterone and cortisol jointly influence reactive aggression in women the dualhormone hypothesis posits that the effect of testosterone on social behavior is moderated by cortisol the present study tested this hypothesis with a competitive reactive aggression paradigm in 53 healthy undergraduate women salivary cortisol and testosterone were assessed at baseline participants were personally insulted and subsequently given the opportunity to retaliate by administering blasts of white noise to the provocateur participants were randomly assigned to win or lose the aggressive competition basal testosterone positively predicted reactive aggression and state dominance but only among participants with high concentrations of basal cortisol the corresponding reverse pattern was found for state submissiveness winners also had higher concentrations of testosterone than losers following the aggressive competition we discuss the role of heightened reactivity to social provocation as a possible explanation for these effects