Darwin's Cathedral, by David Sloan Wilson

Mother Teresa poses a perennial problem for evolutionary biology. How can one explain her selfless giving when natural selection drives us to be selfish? For the evolutionary biologist, Mother Teresa's actions must be either maladaptive or secretly selfish, and some biologists have argued both points. David Sloan Wilson presents a third alternative. Professor of biology and anthropology at Binghamton University, Wilson has built a career on opposing the traditional claim that Darwin's theory of natural selection necessarily leads to selfish behavior. Wilson claims that religion can be fully understood in terms of the forces of human evolution. Why are we religious? Because evolution made us that way. Why does Mother Teresa help others? Because that's what her religion tells her to do.

Wilson's central claim is that the existence, nature and persistence of religion can be understood primarily in terms of group selection. Modern, neo-Darwinism holds that organisms always act so as to promote their own reproductive interests. One should, therefore, expect only limited cooperation in nature. By contrast, Wilson's research has led him to conclude that, in certain circumstances, it is biologically advantageous to engage in strong forms of cooperation and self-sacrifice. In such cases, the group acts as a unit, becoming a kind of super­organism that competes with other groups. When altruistic groups are sufficiently well knit, they will always outperform groups made up of more selfish individuals. Over time, these groups of altruists will be selected for, and genes for altruism will spread through the population. What better cultivates group loyalty than religion? One need only think of the Hutterites and the Jehovah's Witnesses.

The first chapters of Darwin's Cathedral lay out the methodological groundwork of Wilson's thesis that human beings are significantly a product of group selection, and that we are psychologically driven to religious beliefs because they promote group commitment and self-sacrifice. Wilson then applies his thesis to a wide range of case studies, using it to explain the success or failure of groups ranging from egalitarian hunter-gatherers to Korean Christian churches in the United States.