The implicit need for power represents a capacity for experiencing impact on others as rewarding. The power motive operates outside of people's introspective awareness (i.e., measures of implicit power motivation do not correlate with self-report measures of trait dominance or aggression), but influences neural, endocrine, and behavioral responses to social incentives. In this talk, I will present a biobehavioral model of implicit power motivation that assigns a key role to the gonadal steroids testosterone and estradiol in physiological and learning responses to social success, discuss the links between these hormones to power-motive-dependent stress responses and implicit learning of instrumental behavior, and pinpoint brain areas involved in implicit power motivation.