Do nice guys—and gals—really finish last? The joint effects of sex and agreeableness on income.

Sex and agreeableness were hypothesized to affect income, such that women and agreeable individuals were hypothesized to earn less than men and less agreeable individuals. Because agreeable men disconfirm (and disagreeable men confirm) conventional gender roles, agreeableness was expected to be more negatively related to income for men (i.e., the pay gap between agreeable men and agreeable women would be smaller than the gap between disagreeable men and disagreeable women). The hypotheses were supported across 4 studies. Study 1 confirmed the effects of sex and agreeableness on income and that the agreeableness-income relationship was significantly more negative for men than for women. Study 2 replicated these results, controlling for each of the other Big Five traits. Study 3 also replicated the interaction and explored explanations and paradoxes of the relationship. A 4th study, using an experimental design, yielded evidence for the argument that the joint effects of agreeableness and gender are due to backlash against agreeable men.