Research shows that individuals feel and later perform better when given positive feedback in the context of an upright posture, as opposed to a slumped one, even if unaware that their bodily position is meant to express emotion. We sought to determine whether proprioceptive feedback from body postures operate differently for women and men. Participants received success feedback when in either an upright or slumped posture, which was covertly manipulated. Results showed that for men the effects of posture were intuitive and appropriate: receiving success feedback while upright enhanced performance self-ratings. In contrast, after adopting an upright posture, women went on after success feedback to perform more poorly and make more negative self-ratings, than after adopting a slumped posture. A number of theories are offered as potential explanations for this gender effect.