You can accept or reject these particular evolutionary explanations as you like. But the underlying message is worth taking home: Much of what now passes for "natural selection" isn't exactly natural. It's social. As such, it deserves no presumptive respect as a validator or promulgator of objective fitness. Nor does the discovery of a genetic basis for this or that trait prove it's more than a social construct. In the era of cultural selection, many genes are a social construct. Which makes them no less real.
This is neat: