Everyone can agree that ethnocentrism exists. Is it a natural, evolved feeling? Was it selected for in the past? Gregory Cochran says no. In 2012 he wrote a blog post titled “Your country’s not your blood.” He wrote:

I have to disagree with Henry: I don’t think there’s been selection for ethnic nepotism. I somewhat suspect that there may have been recent selection for more accurate altruism, in some populations.

Imagine that in much of history, people lived in small groups that often fought with their neighbors. In that sort of situation, selection for group altruism is at least possible, since the group is full of close relatives, while the opponents are less closely related. Both sides are probably members of the same broad ethnic group or race, but that doesn’t matter : only the kinship coefficients matter.

Suppose that many people emerge on to the stage of history with this impulse to fight for their side: in the past, this always meant closely related people. Now, with the emergence of states, they find themselves fighting in armies, which feel like their side, but are no longer closely related – not a bunch of cousins and such. It could well be that many individuals are actually willing to risk themselves for that state. They’re willing to die for truth, justice and the Assyrian Way. It’s not genetically smart, but their adaptations are wired for past circumstances. In the same way, you might eat saccharin instead of sugar, or date a replicant instead of an actual human female , especially if the replicant looks like Sean Young in Bladerunner.

Over time, this misfiring of altruism should decrease. Patriotism burns itself out. Dying for Assyria doesn’t do your close relatives any good at all. Some people will be more prone to this, some less, and that tendency will be heritable. Those with a tendency to volunteer (in the service of anything other than close relatives) should dwindle away over time. But states are older in some places than others, and some have made greater demands than others. Imagine a region where states have been around longer, a place in which the locals have lived through empire after empire after empire. They should have had the patriotism bred clean out of them. They should feel altruistic about their families, maybe their clan – and nothing else.(Cochran, 2012)