Seminar Three
Warfare, genocide and ethnic conflict
Ingroup and outgroup

Charles Darwin’s brilliant insight that natural selection explains much of evolution was not well accepted until the early twentieth century. We know now that natural selection operates on one or more of several levels, including that of the gene, cell, individual organism or group of organisms (even an entire species).

Can group selection account for the we-they? Could a warlike predisposition evolve through natural selection? If we discover that it can, we would be one step closer to intervention. As it turns out, a study by Jung-Kyoo Choi and Samuel Bowles, published in the journal Science in 2007, reported the results of a theoretical analysis showing that outgroup hostility and ingroup cohesion can favor the survival of one group of people over another. The Abstract of the paper states:

Altruism—benefiting fellow group members at a cost to oneself—and parochialism—hostility toward individuals not of one's own ethnic, racial, or other group—are common human behaviors. The intersection of the two—which we term “parochial altruism”—is puzzling from an evolutionary perspective because altruistic or parochial behavior reduces one's payoffs by comparison to what one would gain by eschewing these behaviors. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to success in these conflicts. Our game-theoretic analysis and agent-based simulations show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans, neither parochialism nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.

The abstract of this study needs some translation. Below is an oversimplified drawing I made to explain it:

At the top of the drawing, friendly people coexist across boundaries. At the bottom a war-prone group at the left consists of members who are altruistic toward each other and hostile toward outsiders; the analysis showed that under conditions likely to have prevailed in early humans, groups with genes predisposing to this tendency would confer greater reproductive success on their group.

This study throws some desperately needed light on the evolutionary roots of warfare, suggesting that a combination of ingroup cohesion and outgroup hostility can exert a group-selectionist advantage. That is, selection can favor the group, even if it doesn't always favor the individual; the warrior who dies in battle testifies to this. Ingroup altruism is shown by the warrior who dies for his countrymen even if he doesn't personally know most of them.

Neither ingroup altruism nor outgroup hostility can provide benefits singly, but together they “share a common fate, with war the elixir of their success.” I found a remarkable observation supporting this conclusion in an article about the Pashtun (Pushtun) people of Afghanistan: “The only time the Pashtun are at peace with themselves is when they are at war.”

The Pashtuns, who live in Afghanistan and Pakistan, have a system of ethics that regards treachery and violence as virtues rather than vices. A man who loses his honor is ostracized, along with his family, and he is obliged to take revenge. He may kill both his daughter's lover and his own daughter.