The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature (24 page)

The real question is whether pleasure-giving courtship imposes any evolutionary costs on the hot choosers. If it did, the hot choosers would evolve a barrier between that form of pleasure and their mate choice system. However, pleasure is not arbitrary in the way that some sensory biases may be arbitrary. Pleasure systems evolve for a reason: they encourage animals to do things that improve their survival and reproduction prospects. Food brings pleasure because our bodies require energy. Predators bring displeasure because they want to kill us. If a hot chooser's pleasure systems are well calibrated, any courtship behavior that brings it pleasure will increase its fitness somehow. The behavior brings evolutionary benefits, not evolutionary costs.

The only remaining worry is that pleasure-giving courtship might not be a very good indicator of an individual's fitness. A hot chooser might favor pleasure at the expenses of good genes. If good genes are very important, and if pleasurable courtship does not correlate with good genes, then the hot choosers should evolve a defensive barrier between their pleasure system and their mate choice system. But I don't think that such a defense would usually be necessary. Remember the basic requirements for a fitness indicator: it should vary perceptibly, and it should be sufficiently costly that low-fitness pretenders cannot fake it. Pleasurable systems evolved in the first place as discriminatory systems very sensitive to variation between situations, so noticing individual variation between sexual prospects should not be a

problem.

So how costly is it to give pleasure? If the pleasure comes from gaining a significant fitness benefit such as food, shelter, protection, or access to good territory, then the pleasure-giver probably incurred significant costs to acquire such a gift. If the pleasure comes from dextrous grooming, brilliant conversation, attentive

foreplay, or prolonged copulation, there are time, energy, and skill costs. Giving pleasure is generally harder than exploiting sensory biases, because pleasure has to reach much deeper into the receiver's brain. For this reason, pleasure-giving courtship behavior is probably a better fitness indicator than courtship that merely activates sensations.

Pleasure-giving is rather different from sensory exploitation. It feels better, it is better at tracking fitness benefits given to oneself, and it works better as a fitness indicator. Hot choosers that use pleasure to mediate mate choice are not more evolutionarily vulnerable than cold choosers. On the contrary, they are better positioned to let sexual selection take them off in new evolutionary directions where unknown pleasures await.

The Ornamental Mind

As discussed in Chapter 1, traditional theories viewed the human mind as a set of survival abilities. The dominant metaphors for mental adaptations were drawn from military and technical domains. Cognitive science views the mind as a computer for processing information. Many evolutionary psychologists view the mind as a Swiss army knife, with distinct mental tools for solving different adaptive problems. Some primatologiste view the mind as a Machiavellian intelligence center devoted to covert operations.

Our discussion of sensory bias theory and pleasure leads to a different view. Perhaps we can do better by picturing the human brain as an entertainment system that evolved to stimulate other brains—brains that happened to have certain sensory biases and pleasure systems. At the psychological level, we could view the human mind as evolved to embody the set of psychological preferences our ancestors had. Those preferences were not restricted to the surface details of courtship like the iridescence of a peacock's tail; they could have included any preferences that lead us to like one person's company more than another's. The preferences could have been social, intellectual, and moral, not just sensory.

This "ornamental mind" theory leads to some quite different metaphors drawn from the entertainment industry rather than the military-industrial complex. The mind as amusement park. The mind as a special-effects science-fiction action film, or romantic comedy. The mind as a Las Vegas honeymoon suite. The mind as a dance club, cabinet of curiosities, mystery novel, computer strategy game, Baroque cathedral, or luxury cruise ship. You get the idea.

Psychologists who pride themselves on their seriousness may consider these metaphors trivial. To them, the mind is obviously a computer that evolved to process information. Well, that seems obvious now, but in 1970 the mind as a computer was just another metaphor. It was just slightly better than Sigmund Freud's metaphor of the mind as a hydraulic system of liquid libido, or John Locke's metaphor of the mind as a blank slate. The mind-ascomputer helped to focus attention on questions of how the mind accomplishes various perceptual and cognitive tasks. The field of cognitive science grew up around such questions.

However, the mind-as-computer metaphor drew attention away from questions of evolution, individual differences, motivation, emotion, creativity, social interaction, sexuality, family life, culture, status, money, power, birth, growth, disease, insanity, and death. As long as you ignore most of human life, the computer metaphor is terrific. Computers are human artifacts designed to fulfill human needs, such as increasing the value of Microsoft stock. They are not autonomous entities that evolved to survive and reproduce. This makes the computer metaphor very poor at helping psychologists to identify mental adaptations that evolved through natural and sexual selection. "Processing information" is not a proper biological function—it is just a shadow of a hint of an abstraction across a vast set of possible biological functions. The mind-as-computer metaphor is evolutionarily agnostic, which makes it nearly useless as a foundation for evolutionary psychology. At the very least, the metaphor of the mind as a sexually selected entertainment system identifies some selection pressures that may have shaped the mind during evolution.

This entertainment metaphor suggests that the human mind shares some features with the entertainment industry. The mind has to be open for business, with a clean, safe, welcoming interior. It needs good public access routes and good advertising. It must provide a world of stimulation, ideas, adventure, interaction, and novelty set apart from the ordinary world of tedium, toil, and threatening uncertainty. It must capture the right market niche, and respond to changing consumer tastes. The mind hides the appalling working conditions of its employees (the energy-hungry brain circuits) to provide attentive, smiling service for visitors. Like the future dystopia in H. G. Wells's
The Time Machine,
the Eloi of leisured ideas appear on the surface of consciousness, while the Morlocks of cognitive effort are imprisoned underground.

If the ornamental mind theory has any merit, then the functional demands that evolution has placed on the human mind have been misunderstood. The entertainment industry does not operate like a military campaign. As Darwin realized, sexual selection does not work like survival of the fittest. All of the criteria of success, the strategies, the resources, and the modes of competition are different.

Viewed from a military point of view, Hollywood is a failure. It hasn't even managed to annex the San Fernando valley, or invade Santa Monica, or bomb Santa Barbara, or establish a secret alliance with Tijuana. Its standing army is just a few hundred studio security guards, and it has no navy or air force. Its people are undisciplined, vain, soft, and prone to fantasy. They live on salad. They would be no match for the Spartans, the Mongols, or the British SAS. This is all true, but rather misses the point. If the human mind evolved as an entertainment system like Hollywood, those of its features that look like military-competitive weaknesses may actually be its greatest strengths. Its propensity for wild fantasy does not undermine its competitive edge, but attracts enormous interest from adoring fans. Its avoidance of physical conflict allows it to amass, quietly and discreetly, enormous resources and expertise to produce ever more impressive shows. Its emphasis on beauty over strength, fiction over fact, and

dramatic experience over plot coherence, reflects popular taste, and popular tastes are what it lives on. Its huge promotional budgets, costly award shows, and conspicuously luxurious lifestyle are not just wasteful vanity—they are part of the show. Its obsession with fads and fashion do not reflect victimization by exploitative memes, but the strategic appropriation of cultural ideas to promote its own products.

Profit is Hollywood's bottom line, and everything about it that would look baffling to Genghis Khan makes perfect sense to entertainment industry analysts who understand what produces profit. To understand the human mind's evolution, we have to remember that reproductive success is evolution's bottom line. The mind makes very little sense as a Swiss army knife or a military command center. It makes more sense as an entertainment system designed to stimulate other brains, and the ornamental mind theory captures that intuition.

The Space of All Possible Stimulation

The entertainment industry can be viewed as an attempt to explore the space of all possible stimulation that can excite the modern human brain. Every movie, every book, every painting, every music CD, and every computer game is a set of potential stimuli that may or may not work. The human brain is fickle: it responds much more positively to some stimulation than to other stimulation. Nobody knows in advance what stimulation will work, though some can make some good guesses. If evolutionary psychologists like me could make solid predictions about exactly what stimulation patterns would optimally excite the human brain, we could just move to Hollywood and become highly paid entertainment industry consultants. But we cannot do much better than ordinary film producers, because a general understanding of typical human reactions to ancestrally normal events does not allow us to predict the human brain's exact reactions to any possible novel stimulation. Modern human culture is a vast, collaborative attempt to chart out this space of all possible stimulation, to discover how to tweak our

brains in pleasurable ways.

The ornamental mind theory suggests that human evolution, like the entertainment industry, pursues promising lines of stimulation that might bring rewards for the producer. Sexual selection explores this space of all possible stimulation, reaching into the perceiver's brain and gauging what excites a positive reaction. Sexual evolution navigates through the brain-space of each species, in search of mutual pleasure and reproductive profit.

Imagine a species that stumbles into an evolutionary utopia in which sexual selection is no longer driven by male competition for dominance and display but by mutual choice for mutual pleasure. The males who deliver the greatest rapture to females are sexually favored, passing on the pleasure-giving abilities to both sons and daughters. Equally, those females who deliver the greatest bliss and contentment to males are favored, passing on their pleasure-giving abilities to their offspring. Each generation provides more pleasure than the last, and receives more. The species spirals upward into rapture, leaving behind all the genes for unpleasantness, unkindness, inattentiveness, and poor foreplay.

If only. The trouble with mutual choice for mutual pleasure is that all the genes for unpleasantness come aboard as stowaways. Mutual choice implies that individuals sort themselves out in a mating market. As a thought experiment, imagine for the moment that mating is perfectly monogamous. The best pleasure-giving female pairs up with the best pleasure-giving male. Both have their sexual preferences fulfilled, and they live in bliss and produce pleasure-giving children. But their competitors do not just give up and die of embarrassment at the inferiority of their foreplay. Moderately pleasant females mate with moderately pleasant males, because neither can do any better in the mating market. And the most unpleasant females mate with the most unpleasant males, because their only alternative would be to remain single. All else being equal, they will all have children too. In fact, assuming monogamy, the genes for pleasure-giving will not have any reproductive advantage whatsoever over the genes for imposing unspeakable misery on one's sexual partner.

Mutual choice for mutual pleasure will determine which sexual

relationships form, but will not increase pleasure from one generation to the next. The sexual choice would not result in any real sexual selection. It would reshuffle genes but would not change which genes persist in the population. It would not make evolution happen. Given monogamy, mutual choice for pleasure is only pseudo-selection. It looks like sexual selection, but it doesn't change genes like sexual selection.

Pleasure alone is not enough. We need either more sexual competition than monogamy provides, or some interaction between sexual selection for entertainment and other sexual selection processes. The ornamental mind theory tends to overlook the interactions between brains as entertainment producers and brains as entertainment consumers. We must remember the possibility of runaway effects, where entertainment consumers become more and more demanding. The ornamental mind theory also ignores the problem of consumer boredom. On evolutionary time-scales, consumers may simply lose interest in useless stimulation. They may simply walk out of sexual selection's amusement park if their sexual choices are not delivering good genetic value. In modern human culture, consumers can be treated as passive systems with stable tastes that can be exploited. But in evolution, entertainment-consumers can evolve as fast as entertainment-producers can. Neither has the upper hand. We have to put the ornamental mind theory together with the fitness indicator theory to explain why some sexual ornaments stick around.

Putting the Pieces Together