A Martian looking down on planet Earth might note all this with puzzlement. Why do humans fool around so much when there is, inevitably, work to be done? Although other species have been known to play, no other species goofs around so much, or in so many ways. Only a few other species seem to spend much time having non-procreative sex, and none (outside labs run by inquisitive humans) watch television, go to rock concerts, or play organized sports. Which raises the question, is pleasure really an ideal adaptation, or (with apologies to Shakespeare) is there something klugey in Denmark?
Aha, says our Martian to itself; humans are no longer slaves to their genes. Instead of engaging in the activities that would yield the most copies of their genes, humans are trying to maximize something else, something more abstract — call it “happiness” — which appears to be a measure of factors such as a human’s general well-being, its level of success, its perceived control over its own life, and how well it is regarded by its peers.
At which point, our Martian friend would be even more confused. If people are trying to maximize their overall well-being, why do they do so many things that in the long run yield little or no lasting happiness?
Perhaps nothing would puzzle this Martian more than the enormous amount of time that many people spend watching television. In America, the average is 2-4 hours per day. If you consider that the average person is awake for only 16, and at work for at least 8, that’s a huge proportion of the average person’s discretionary time. Yet day after day, audiences watch show after show, most containing either stories of dubious quality about fictional people or heavily edited “reality” portraits of people in improbable situations that the average viewer is unlikely ever to meet. (Yes, public television airs some great documentaries, but they never draw the ratings of Law & Order, L.O.S.T., or Survivor.) And here’s the kicker: hard-core television watchers are, on average, less happy than those who watch only a little television. All that TV viewing might convey some sort of short-term benefit, but in the long term, an hour spent watching television is an hour that could have been spent doing something else — exercising, working on hobbies, caring for children, helping strangers, or developing friendships.
And then there are, of course, chemical substances deliberately designed to shortcut the entire machinery of reward, directly stimulating the pleasure parts of the brain (for example, the nucleus accumbens). I’m speaking, of course, of alcohol, nicotine, and drugs like cocaine, heroin, and amphetamines. What is remarkable about these substances is not the fact that they exist — it would be almost impossible to build a chemically based brain that wouldntbe vulnerable to the machinations of clever chemists — but rather the extent to which people use them, even when they realize that the long-term consequences may be life threatening. The writer John Cheever, for example, once wrote, “Year after year I read in [my journals] that I am drinking too much… I waste more days, I suffer deep pangs of guilt, I wake up at three in the morning with the feelings of a temperance worker. Drink, its implements, environments, and effects all seem disgusting. And yet each noon I reach for the whiskey bottle.”
As one psychologist put it, addictions can lead people down a “primrose path” in which decisions made in the moment seem — from the strict perspective of temporary happiness — to be rational, even though the long-term consequences are often devastating.
Even sex has its puzzling side. That sex is enjoyable is perhaps no surprise: if sex weren’t fun for our ancestors, we simply wouldn’t be here. Sex is, after all, the royal road to conception, and without conception there would be no life. Without life, there would be no reproduction, and legions of “selfish genes” would be out of work. It seems like a no-brainer that creatures that enjoy sex (or at least are driven toward it) will outpropagate those that do not.
But having a taste for sex is not the same as pursuing it nonstop, to the virtual exclusion of anything else. We all know stories of politicians, priests, and plain ordinary folk who destroyed their life in relentless pursuit of sex. Might a Martian question whether our contemporary need for sex is as miscalibrated as our need for sugar, salt, and fat?
The Martian would eventually come to realize that although the core notion of pleasure as motivator makes a good deal of sense, the pleasure system as a whole is a kluge, from top to bottom. If pleasure is supposed to guide us to meet the needs of our genes, why do we humans fritter away so much of our time in activities that don’t advance those needs? Sure, some men may skydive to impress the ladies, but many of us ski, snowboard, or drive recklessly even when nobody else is watching. When such a large part of human activity does something that risks “reproductive fitness,” there must be some explanation.
And indeed there is, but it’s not about minds that are optimal, but about minds that are clumsy. The first reason should, by now, seem familiar: the neural hardware that governs pleasure is, like much of the rest of the human mind, split in two: some of our pleasure (like, perhaps, the sense of accomplishment we get from a job well done) derives from the deliberative system, but most of it doesn’t. Most pleasure springs from the ancestral reflexive system, which, as we have seen, is rather shortsighted, and the weighting between the two systems still favors the ancestral. Yes, I may get a slight sense of satisfaction if I waive my opportunity to eat that crème brûlée, but that satisfaction would almost certainly pale in comparison to the kick, however brief, that I would get from eating it.[41] My genes would be better off if I skipped dessert — my arteries might stay open that much longer, allowing me to gather more income and take better care of my future offspring — but those very genes, due to their lack of foresight, left me with a brain that lacks the wisdom to consistently outwit the animalistic parts of my brain, which are a holdover from an earlier era.
The second reason is more subtle: our pleasure center wasn’t built for creatures as expert in culture and technology as we are; most of the mechanisms that give us pleasure are pretty crude, and in time, we’ve become experts at outwitting them. In an ideal world (at least from the perspective of our genes), the parts of our brain that decide which activities are pleasurable would be extremely fussy, responding only to things that are truly good for us. For example, fruits have sugar, and mammals need sugar, so it makes sense that we should have evolved a “taste” for fruit; all well and good. But those sugar sensors can’t tell the difference between a real fruit and a synthetic fruit that packages the flavor without the nutrition. We humans (collectively, if not as individuals) have figured out thousands of ways to trick our pleasure centers. Does the tongue like sweetness of fruit? Aha! Can I interest you in some Life Savers? Orange soda? Fruit juice made entirely from artificial flavors? A ripe watermelon may be good for us, but a watermelon-flavored candy is not.
And watermelon-flavored candy is only the start. The vast majority of the mental mechanisms we use for detecting pleasure are equally crude, and thus easily hoodwinked. In general, our pleasure detectors tend to respond not just to some specific stimulus that might have been desirable in the environment of our ancestors, but to a whole array of other stimuli that may do little for our genes. The machinery for making us enjoy sex, for example, causes us to revel in the activity, just as any reasonable evolutionary psychologist would anticipate, but not just when sex might lead to offspring (the narrowest tuning one might imagine), or even to pair bonding, but much more broadly: at just about any time, under almost any circumstance, in twos and threes and solo, with people of the same sex and with people of the opposite sex, with orifices that contribute to reproduction and with other body parts that don’t. Every time a person has sex without directly or indirectly furthering their reproductivity, some genes have been fooled.
41
My friend Brad, who hates to see me suffer abstemiously in the service of some abstract long-term good, likes to bring me to a restaurant called Blue Ribbon Sushi, where he invariably orders the green tea crème brûlée. Usually, despite my best intentions, we wind up ordering two.