There is often one person in a friendship group who rarely hesitates to spend. They pick up the dinner bill, arrive with unexpectedly thoughtful gifts, buy concert tickets for everyone or insist that a struggling friend does not need to pay them back. From the outside, this behavior can look like simple generosity. Psychology, however, offers a more interesting explanation. Spending generously on friends can involve prosocial spending, communal relationship orientation, relatedness, social connection and the emotional reward of giving. Research even suggests that under certain circumstances, using money for another person can produce more happiness than spending it on yourself.