According to Satoshi Kanazawa in Time:
Intelligent people are more likely to be nocturnal because humans are designed to wake up when the sun comes up and go to sleep when the sun goes down. They are more likely to be homosexual, because humans are evolutionarily designed to reproduce heterosexually. They are more likely to enjoy instrumental music because music in its evolutionary origin was vocal, and they are more likely to consume alcohol, cigarettes and drugs because all of these substances are evolutionarily novel.
Kanazawa’s basic premise is that intelligent people are less good at doing “important” things than “less intelligent people” because,
Most of the problems that we have to solve today—how to excel in school, how to find jobs, how to do virtually everything on a computer—are evolutionarily novel. So intelligent people do well in almost every sphere of modern life, except for the most important things, like how to find a mate, how to raise a child, how to make friends. Intelligence does not confer any advantage for solving all the evolutionarily familiar problems that our ancestors encountered. More intelligent people do not have any advantage in finding mates and often have disadvantages.
It’s an interesting argument, but he takes it to a ridiculous extreme in order — yes, you’ve guessed it — to claim that liberals and atheists are more intelligent than conservatives and the religious. And lest you think I’m taking the argument to an unfair extreme in turn, note that Kanazawa wrote a whole paper called . . . Why Liberals and Atheists Are More Intelligent.
In his book, Kanazawa contends, inter alia, that liberals are more intelligent because they do things that buck evolutionary purposes; whereas conservatives are slaves to those traditions. Okay, but one has to ask why the author doesn’t go even further. Here is a modest set of suggestions: Intelligent people are more likely to stick knives into their eyes, because evolution engenders in us a sense of self-preservation. Intelligent people are more likely to ingest vast quantities of metal polish because it was unavailable for most of human history and is thus evolutionarily novel. They are more likely to try and fly off the top of skyscrapers because men were designed to walk on their hands and feet. Intelligent people are more likely to murder their children because mammals evolved to look after their offspring and to do so runs against the reproductive imperative.
Unsurprisingly, none of those things are claimed. Perhaps this is because unlike classical music, homosexuality, nocturnal habits, and drug use, they fit in neither with liberal policy preferences nor the more general thesis that so many have taken it upon themselves to advance in the last few years: That conservatives are empirically stupid or sick, and that liberalism is a sign of superior intellect.