Biological evolutionary processes select for heritable behaviors providing a survival and reproductive advantage. Accordingly, how we behave is, at least in part, affected by the evolutionary history of our species. This research uses evolutionary psychology as the theoretical perspective for exploring the relationship between a heritable biological characteristic (testosterone level) and an important business behavior (new venture creation). Data were collected from 31 MBA students with significant prior involvement in new venture creation and from 79 other student subjects with no new venture start-up experience. Consistent with evolutionary psychological theory, the biological (testosterone level) effect upon behavior (new venture creation) is partially mediated by the psychological (risk propensity). (Contains 1 figure and 4 tables.)