Editing Haidt 2012 (section)

===Victorious Tribes:===

*In The Descent of Man, Darwin made the case for group selection, raised the principal objection to it, and then proposed a way around the objection.

*The example Darwin talks about is of two tribes: one of courageous, sympathetic, and faithful members, another of selfish and contentious members. The first tribe would succeed better and conquer the other. Hence, the tribe rich in these qualities would spread and be victorious over other tribes.

*However, Darwin also discussed the free rider problem, which is the main objection against group selection: How within the same tribe did a large number of members first become endowed with these social and moral qualities, and how was the standard of excellence raised?

*When groups compete, the cohesive, cooperative group usually wins. But within each group, selfish individuals (free riders) come out ahead. They share in the group’s gains while contributing the least.
The solution to this lies in multilevel selection. Multilevel selection refers to a way of quantifying how strong the selection pressure is at each level, which means how strongly the competition of life favors genes for particular traits.

*The suicidal self-sacrifice genes are more favored at the group level, but are very strongly opposed by selection at the individual level. Once humans had the minimal ability to band together and compete with other groups, then group-level selection came into play and the most groupish groups had an advantage over groups of selfish individualists.

*In many effective groups, such as armies, there are structures in place to suppress selfishness. Any time a group finds a way to suppress selfishness, it changes the balance of forces in a multi-level analysis. Individual-level selection becomes less important, and group-level selection becomes more powerful. 

*For nearly a hundred years, people accepted this claim of certain behaviors being “for the good of the group”. However, these claims were naive because individuals that blindly followed the selfless strategy would leave fewer surviving offspring and would soon be replaced in the population by the descendants of free riders.

*In 1996, this loose thinking was brought to a half, along with almost all thinking about group selection.