There's another way to look at this. I can see how evolution would select for these strategies: #1: Punish people who don't go along with the group. While t

There's another way to look at this. I can see how evolution would select for these strategies: #1: Punish people who don't go along with the group. While the person loses $5 in the short run, the message is clear: cooperation or nothing. #2: There is a heuristic that remembers past decisions so that we don't have to recalculate them again. That saves energy and time.