Males and evening types report greater risk-taking; only females show significant differences in risk-taking across self-reported circadian phenotypes. (A) Males have greater risk propensity compared to females (F(1,570) = 5.160, p = 0.023) and evening-types overall have greater risk propensity than either intermediate or morning-types (F(2,570) = 9.097, p<0.001). Among females, evening types had significantly greater risk propensity than morning or intermediate types (F(2,358) = 11.331, p<0.001; Tukey’s homogenous subsets post-hoc analysis). (B) Risk-taking behavior on the BART was significantly higher in males than females (F(1,570) = 17.631, p<0.001). Female evening types show higher risk-taking if intermediates and morning types are pooled (t = 2.20, df = 356, p = 0.028).