Schizophrenia is the price we pay for minds poised near the edge of a cliff

"The persistence of schizophrenia is an evolutionary enigma. It is a disabling psychiatric condition that reduces the likelihood of having children, and yet it has roughly 1% lifetime prevalence worldwide. Traditional evolutionary hypotheses, such as those invoking kin selection, mutation-selection balance, and evolutionary mismatch don’t quite explain this."

Much the same could be said for gayness. If it were genetic, it should have been eliminated by evolution by now. Which suggests that it's not.

There are some differences in incidence of schizophrenia in populations.[1] Birth order matters, slightly, with prevalence higher for firstborns. (This is the reverse of homosexuality and left-handedness.) Migrants have higher rates of schizophrenia than non-migrants. Women vs. men, about the same. Rural vs. urban, about the same.

What the original paper suggests is that they didn't discover anything significant. It's more like a discussion of feedback control problems near a cliff, but by people who don't know about that part of control theory.

The title is overly dramatic for the results.

[1] https://journals.plos.org/plosmedicine/article?id=10.1371/jo...

> Much the same could be said for gayness. If it were genetic, it should have been eliminated by evolution by now. Which suggests that it's not.

There are very plausible explanations for the genetic basis of gayness. One is that being gay is essentially a "byproduct" of higher fecundity in women - I'd have to search for the study, but gay men with sisters tend to have sisters with more kids than the norm.

The other is the "guncle" hypothesis (which is related to the previous one). While gay men and women do not have their own biological children (at least through gay relationships), they are able to spend additional resources on their nieces and nephews. Anecdotal obviously, but it certainly worked this way in my family. As a guncle I helped pay for my niece's education (and was happy to do so because I don't have to care for children of my own ).