Paul Rubin has an editorial in the Washington Post about how evolution may result in a proclivity towards economic and social conflict:

Conflict was common in the environment in which humans evolved. As primates, which are a very social order, our ancestors lived in relatively small groups in which everyone knew everyone else. Our minds are adapted to deal with populations of that size. Our ancestors made strong distinctions between members of the in-group and outsiders, and we still make such distinctions today -- social psychologists can create in-group and out-group feelings based on virtually any arbitrary difference between populations.

The in-group and out-group intuitions help fuel opposition to expanded trade and immigration. The public intuitively believes that the beneficiaries of such policies will be foreigners, and it is easy to arouse suspicion about those who are not part of our in-group. When coupled with zero-sum thinking, this is a powerful political tool. For instance, a domestic industry or collection of domestic workers, when having difficulty competing with foreign or immigrant competitors, can use innate dislike of outsiders when advocating for increased barriers.

As the evolutionary inheritors of small-group societies, our minds sometimes have difficulty appreciating risks, harms and benefits experienced by a large population. In a group of 100 people, when we observe something that has happened to someone, it is a reasonably likely event. In a society of 300 million, when we learn about something happening to one person, it may be an extremely unlikely event, but we often perceive it as likely when we see it on the news. This instinct also shapes our perspective on trade and immigration. We understandably have great sympathy for workers who lose their jobs because they can't compete with foreign workers, but we have difficulty appreciating the benefit that our nation of consumers gains from the products of foreign laborers.

As products of evolution, humans cannot help but be born with certain biases. But we are not condemned to this evolutionary programming; we can identify the biases and recognize when they lead us astray in the modern world. American history is marked by many periods of openness to trade and immigration, and those periods have often featured strong economic growth and human prosperity. However, American history has also seen many instances in which our zero-sum and anti-outsider intuitions reemerged, whether in the form of prohibitions against "dogs or Irishmen" or policies against "outsourcing."

Read the whole thing.

He is basically making an argument that in order to achieve things like free trade and free immigration we have to overcome our innate tendencies towards conflict.

It is an interesting argument that human beings possess an almost ethological tendency to seek out conflict, to divide ourselves into in-groups and out-groups. This tendency has long been recognized in the social psychology literature starting with the canonical experiment by Muzafer Sherif in 1966. (In the experiment, children were arbitrarily divided into groups at a summer camp. The researchers found that positive feelings to individuals within each group and negative feelings to those outside the group develop spontaneously.)

On the other hand, numerous experiments in game theory -- not to mention the same Sherif 1996 experiment -- show that cooperation can also develop spontaneously under the right circumstances.

In this sense, I agree with what Rubin is saying, but I think the emphasis of his piece is off. He seems to be arguing that if we emphasize the cooperative components of our nature than they will become more prominent, that larger cooperative units will develop. The trend historically seems to bear this out. (Look at the rise of national entities that are completely divorced from any sense of common lineage.)

However, I don't know if I buy the contention that the steady state between cooperation and conflict can be manipulated so easily. If Rubin is indeed correct that both tendencies are innate -- and I think that he is -- wouldn't we expect everyone to reach a steady state of balance between the two that would be relatively resistant to change? I think of the balance between cooperation and conflict as an emergent property of human societies, not something that can be easily predicted much less changed by policy.

Further, maybe it is just an issue of tone, but I don't trust bold generalization made about how human evolution affects individuals behavior today. They are usually made in haste and with a dearth of evidence.

Feel free to comment if you think I am reading this wrong, but while I agree with free trade and free immigration as policy decisions I don't think that evolution provides good arguments for them.

Hat-tip: Marginal Revolution.