Book review: Why Humans Cooperate: A Cultural and Evolutionary Explanation by Joseph Henrich, Natalie Henrich.
This book provides a clear and informative summary of the evolutionary theories that explain why people cooperate (but few novel ideas), and some good but unexciting evidence that provides a bit of support for the theories.
One nice point they make is that unconditional altruism discourages cooperation – it’s important to have some sort of reciprocity (possibly indirect) for a society to prevent non-cooperators from outcompeting cooperators.
The one surprising fact uncovered in their field studies is that people are more generous in the Dictator Game than in the Ultimatum Game (games where one player decides how to divide money between himself and another player; in the Ultimatum Game the second player can reject the division, in which case neither gets anything). It appears that the Ultimatum Game encourages people to think in terms of business-like interactions, but in the Dictator Game a noncompetitive mode of thought dominates.