Fig. 1

Screenshot of the mini-dictator game in the time-free condition. In this game, the subject can either press key “J” to choose the selfish option (Option B) which has a higher payoff for herself (95 vs. 85 in this example) or press key “F” to choose the pro-social option (Option A) which has a higher payoff for the other participant (21 vs. 18 in this example). The text is enlarged for display purposes. Refer to Supplementary Fig. 1 for actual screenshots