David Sloan Wilson is a persuasive proponent of multilevel selection theory.  His 2007 article entitled: “Multilevel Selection Theory and Major Evolutionary Transitions:  Implications for Psychological Science” is a good synthesis.  The main argument is that when between-group selection dominates within-group selection, a major evolutionary transition occurs and the group becomes a new higher level organism.  Within groups, altruistic behavior is selectively disadvantageous, but it may be favored between groups and thus counteract the within group selection.  The big question is whether or not this between group selection is always weak so that it is unimportant.  The answer seems to be that between group selection is only rarely strong, but that does not mean that it is unimportant. Wilson states: “All species of eusocial insects are thought to be derived from only 15 original transitions.”    It is thought that it occurred only once among primates to create humans.

A major transition requires mechanisms that suppress conflicts among individuals-internal social control mechanisms.  In humans, moral systems guarded egalitarianism that characterized hunter-gatherer societies.  Members’ motivation to punish selfish behavior results in high levels of cooperation.  Moral intuition comes first and is only partially overridden by moral reasoning.  Multilevel selection theory explains why ingroup favoritism and outgroup hostility are the hallmarks of social psychology.

The human transition enabled our ancestors to cover the earth as a single species. This transition has three major implications.  First, Wilson compares our capacity for rapid cultural adaptation to our immune systems. This is to say that it is complicated and sophisticated.  We do not understand it now.  Second, music, dance, art, literature, and religion are adaptations that might play an essential role in defining groups and fostering cooperation. Third, cultural evolution can create psychological differences among people which are no less profound for being cultural rather than genetic.  Richard Nisbett has pointed out that “psychologists who choose not to do cross-cultural psychology may have chosen to be ethnographers instead.”

Richard Nisbett in Geography of Thought provides interesting insights into such differences.  He divides the world into Easterners and Westerners.  Easterners have difficulty in recognizing changes in objects, while Westerners cannot recognize changes in backgrounds.  Eaterners believe that the world is complicated and inscrutable.  Westerners believe that they can understand the world. Westerners create simple and useful models that can be tested, but tend to focus on the object and slight the possible role of context.  Westerners are particularly susceptible to the fundamental attribution error–thinking other people’s actions are explained by what they are, while my actions are explained by circumstances.  The table below sets out some more distinctions.