The final irony, of course, is that even though sex is incredibly motivating, people often have it in ways that are deliberately designed not to produce children. Heterosexuals get their tubes tied, gay men continue to have unprotected sex in the era of HIV, and pedophiles pursue their interests even when they risk prison and community censure. From the perspective of genes, all of this, aside from sex for reproduction or parental pair bonding, is a giant mistake.
To be sure, evolutionary psychologists have tried to find adaptive value in at least one of these variations (homosexuality), but none of the explanations are particularly compelling. (There is, for example, the “gay uncle” hypothesis, according to which homosexuality persists in the population because gay people often invest considerable resources in the offspring of their siblings.)[42] A more reasonable accounting, in my view, is that homosexuality is just like any other variation on sexuality, an instance of a pleasure system that was only broadly tuned (toward intimacy and contact) rather than narrowly focused (on procreation) by evolution, co-opted for a function other than the one to which it was strictly adapted. Through a mixture of genetics and experience, people can come to associate all manner of different things with pleasure, and proceed on that basis.
The situation with sex is fairly typical. A substantial portion of our mental machinery seems to exist in order to assess reward (a proxy for pleasure), but virtually all of that machinery allows a broader range of options than might (from a gene’s-eye view) be ideal. We see this with enjoyment of sugar — a hot fudge sundae just about always brings pleasure, whether we need the calories or not — but also with more modern compulsions, like addiction to the Internet. This compulsion presumably begins with an ancestral circuit that rewarded us for obtaining information. As the psychologist George Miller put it, we are all “informavores,” and it’s easy to see how ancestors who liked to gather facts might have outpropagated those who showed little interest in learning new things. But once again we have a system that hasn’t been tuned precisely enough: it’s one thing to get a kick from learning which herbs help cure open wounds, but another to get a kick from learning the latest on Angelina and Brad. We would probably all be better off if we were choosier about what information we sought, à la Sherlock Holmes, who notoriously didn’t even know that the earth revolved around the sun. His theory, which we could perhaps learn from, goes like this:
A man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it… It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.
Alas, Sherlock Holmes is only fictional. Few people in the real world have information-gathering systems as disciplined or as finely tuned as his. Instead, for most of us, just about any information can drive our pleasure meters. Late at night, if I allow myself access to the Internet, I’m liable to click here (World War II), click there (Iwo Jima), and then mindlessly follow another link (Clint Eastwood), only to stumble on a fourth (Dirty Harry), rapidly chaining my way from topic to topic, with no clear destination in mind. Yet each tidbit brings me pleasure. I’m not a history scholar, I’m not a film critic; its unlikely that any of this information will ever come in handy. But I can’t help it; I just like trivia, and my brain isn’t wired precisely enough to make me more discriminating. Want to stop my web surfing? Go ahead, make my day.
Something similar happens in our eternal quest for control. Study after study has shown that a sense of control makes people feel happy. One classic study, for example, put people in a position of listening to a series of sudden and unpredictable noises, played at excruciatingly random intervals. Some subjects were led to believe that they could do something about it — press a button to stop the noise — but others were told that they were powerless. The empowered subjects were less stressed and more happy — even though they hardly ever actually pressed the button. (Elevator “door close” buttons work on a similar principle.) Again, there would be adaptive sense in a narrowly focused system: organisms that sought out environments in which they had a measure of control would outcompete those that left themselves entirely at the mercy of stronger forces. (Better, for example, to wade in a slowly moving stream than a full-on waterfall.) But in modern life, we trick the machinery that rewards us for a sense of accomplishment, spending hours and hours perfecting golf swings or learning how to create a perfect piece of pottery — without discernibly increasing the number or quality of our offspring.
More generally, modern life is full of what evolutionary psychologists call “hypernormal stimuli,” stimuli so “perfect” they don’t exist in the ordinary world: the anatomically impossible measurements of Barbie, the airbrushed sheen of a model’s face, the fast, sensation-filled jump cuts of MTV, and the artificial synthesized drum beats of the nightclub. Such stimuli deliver a purer kick than anything could in the ancestral world. Video games are a perfect case in point; we enjoy them because of the sense of control they afford; we like them to the extent that we can succeed in the challenges they pose — and we cease to enjoy them the minute we lose that sense of a control. A game that doesn’t seem fair doesn’t seem fun, precisely because it doesn’t yield a sense of mastery. Each new level of challenge is designed to intensify that kick. Video games aren’t just about control; they are the distillation of controclass="underline" hypernormal variations on the naturally rewarding process of skill learning, designed to deliver as frequently as possible the kick associated with mastery. If video games (produced by an industry racking up billions of dollars in sales each year) strike some people as more fun than life itself, genes be damned, it is precisely because the games have been designed to exploit the intrinsic imprecision of our mechanism for detecting pleasure.
In the final analysis, pleasure is an eclectic thing. We love information, physical contact, social contact, good food, fine wine, time with our pets, music, theater, dancing, fiction, skiing, skateboarding, and video games; sometimes we pay people money to get us drunk and make us laugh. The list is virtually endless. Some evolutionary psychologists have tried to ascribe adaptive benefits to many of these phenomena, as in Geoffrey Miller’s suggestion that music evolved for the purpose of courtship. (Another popular hypothesis is that music evolved for the purpose of singing lullabies.) Miller’s flagship example is Jimi Hendrix:
This rock guitarist extraordinaire died at the age of 27 in 1970, overdosing on the drugs he used to fire his musical imagination. His music output, three studio albums and hundreds of live concerts, did him no survival favours. But he did have sexual liaisons with hundreds of groupies, maintained parallel long-term relationships with at least two women, and fathered at least three children in the U.S., Germany, and Sweden. Under ancestral conditions before birth control, he would have fathered many more.
42
The trouble is there’s no evidence that all that good uncleing (for relatives that are only one-eighth genetically related) offsets the direct cost of failing to reproduce. Other popular adaptationist accounts of homosexuality include the Sneaky Male theory (favored by Richard Dawkins) and the Spare Uncle theory, by which an uncle who stays home from the hunt can fill in for a dad who doesn’t make it home.
If homosexuality is a sort of evolutionary byproduct, rather than a direct product of natural selection, does that make it wrong to be gay? Not at all; the morality of sexuality should depend on