--- - |2 Children (predominantly white and middle class) between 3 and 6 years (M = 55.12 months, N = 145 at Time 1, N = 102 at Time 2) participated in the prosocial choice test at two time points approximately 10 months apart. Children could share with strangers, close friends, nonfriends, and in a control, no recipient condition. Children shared more rewards with friends over time. Age interacted with recipient type such that older children had a higher probability of prosocial allocations toward friends and strangers compared to younger children. Theory of mind (ToM) predicted more prosocial allocations to friends over time, and the youngest children with higher ToM scores showed the largest increase in sharing with friends over time. - Child Development, EarlyView.