The last time was a while back when I said be grateful diversity reduces trust. Now,via Ilkka, I came across Jason Malloy coming out the better (in my uninformed opinion) in intellectual debate with anthropologist Peter Frost (as well as some other random yahoos on the internet). In contrast to the “Bare Branches” theory, Jason claimed that “sexually deprived men are well-behaved, socially beneficial men.” I don’t know why I hadn’t thought of that, since I had repeated Tim Harford’s bit about the effects of supply and demand in places with high rates of male incarceration for blacks. Rather than subsidizing surrogate mothers to have daughters, as one commenter suggested, we should stack the deck in favor of male births, creating a “reserve army of the [reproductively] unemployed” that will keep the rest in line. As a bonus, this helps explain why Mexican immigrants have surprisingly low crime rates, which shoot up in the next generation. As Jason says later in the (long) thread “the sex ratio of different immigrant groups has predicted their social pathology. Groups with many males and few females resulted in more family formation and harder working males.”

One thing I don’t get from Jason’s explanation: why is the sex-ratio biased for males at birth? This conflicts with what I said about gender ratios just recently. If males are more likely to die, that just makes having a male more risky. The total fitness of males and females must be equal, the fitness of those early dying males is zero (dragging down the average male fitness), so why is it advantageous for a woman to give birth to a male? Perhaps many deaths occur before too many resources have been invested?

Finally, Jason Malloy should have his own blog and post regularly. He is one of the highest quality commenters on the net. I don’t know how an artist wound up so informed on the scientific literature, but hats off to him.