(a) The gambles were piloted in N = 54 behavioral participants. These pilot data verified that the chosen payoff amounts and format were appropriate for revealing individual differences in risk preferences. As in Holt & Laury10, participants were risk averse, with the mean indifference ('switch over') point between the high payoff probabilities of 60 and 70%, to the right of risk neutral (dotted line, between 40 and 50%). (b) Individual risk preferences were estimated from Solo trial choices from the main study and indicated risk aversion (ρ < 1) for a majority of participants. (c ) Mix Info trials are those in which the others’ displayed decisions were mixed (one safe, one risky gamble displayed). Regardless of the order of the mixed information (‘Player 1 safe, Player 2 risky’, orange; or ‘Player 1 risky, Player 2 safe’, green), participants’ choices were comparable with that of Solo trials (black). Eight participants whose choices yielded no unique solution for the Solo risk preference estimates were excluded from these plots. Error bars show s.e.m.