We summarize our two sets of controlled experiments designed to see whether single-sex classes within co-educational environments modify students' risk-taking attitudes. In Booth and Nolen (2012b), subjects are in school years 10 and 11, while in Booth et al. (2014), they are first-year university students randomly assigned to single-sex and co-educational classes. Both studies show that while on average females are significantly less likely than men to make risky choices, on exposure to single-sex environments they behave the same as the males. Thus, part of the observed gender difference in behaviour under uncertainty found in previous studies might reflect social learning rather than inherent gender traits.