Figure 1.

(A) In the social condition, subjects chose between keeping the original endowment or investing their endowment in a social partner. (B) In the non-social condition, subjects chose between keeping the original endowment or taking a gamble in which their payoff was determined by a non-social probabilistic mechanism (i.e., roulette wheel). (C) Decision phase activity was modeled across the first 4 s that options were presented (green), while outcome-related neural activity was modeled as the instantaneous response to the revealed outcome (purple).