Males compete for quantity of females, and females compete for quality of males.

One might think that two children should be enough for each man, because that would sustain the population size. But that implies that evolution is for the good of the species, which it is not. The genes of sexually ambitious men would have quickly replaced the genes of men satisfied with just one sexual partner and two children.

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.

When a woman returns home from a long trip, her partner tends to produce a much larger ejaculate than normal, as if to overwhelm any competitor’s sperm that may have found its way into his unwatched partner’s vagina.

Many female mammals (unconsciously) squeeze the ejaculate of some males back out after copulation — a process called «flowback» — as if rejecting sperm from males whose copulation is not up to their standard.

Adults playing sports care intensely about rule violations. If sports were just arbitrary cultural pastimes, why should competitors care so much about developing good rules? Fundamentally, I think they care about rules because they have a shared interest in presenting the sport as a good fitness-indicator to observers of the opposite sex. Obviously, competitors have conflicting interests in terms of who wins. But they all want their sport to be perceived as «cool», so that winning yields social status and sexual rewards.

An Olympic medal in swimming can be more sexually attractive than erotic dancing because swimming is a better fitness indicator.

If you could interview a male Satin Bowerbird for Artforum magazine, he might say something like «I find this implacable urge for self-expression, for playing with color and form for their own sake, quite inexplicable. I cannot remember when I first developed this raging thirst to present richly saturated color-fields within a monumental yet minimalist stage-set, but I feel connected to something beyond myself when I indulge these passions. When I see a beautiful orchid high in a tree, I simply must have it for my own. When I see a single shell out of place in my creation, I must put it right. Birds-of-paradise may grow lovely feathers, but there is no aesthetic mind at work there, only a body’s brute instinct. It is a happy coincidence that females sometimes come to my gallery openings and appreciate my work, but it would be an insult to suggest that I create in order to procreate. We live in a post-Freudian, post-modernist era in which crude sexual meta-narratives are no longer credible as explanations of our artistic impulses».

Fortunately, bowerbirds cannot talk, so we are free to use sexual selection to explain their work, without them begging to differ. With human artists things are rather different. They usually view their drive to artistic self-expression not as something that demands an evolutionary explanation, but as an alternative to any such explanation. They resist a «biologically reductionist» view of art. Or they buy into a simplistic Freudian view of art as sublimated sexuality, as when Picasso repeated Renoir’s quip that he painted with his penis. My sexual choice theory, however, is neither biologically nor psychologically reductionist. It views our aesthetic preferences and artistic abilities as complex psychological adaptations in their own right, not as side-effects of a sex drive. Bowerbirds have evolved instincts to construct bowers that are distinct from the instinct to copulate once a female approves of the bower. We humans have evolved instincts to create ornaments and works of art that are distinct from the sexual instincts behind copulatory courtship. Yet both types of instinct may have evolved through sexual selection.

The fitness indicator theory can explain some embarrassing questions that ordinary people ask when they are admitted to modern art museums. A common reaction to abstract expressionist painting is to dismiss it by saying «My child could have done that», «Any idiot could have done that», or «Even a monkey could have done that». Instead of condescending at such comments, we should ask what sort of aesthetic instincts they reveal. To say «My child could have done that» could mean «I cannot discern here any signs of learned skill that would distinguish an adult expert from an immature novice». The «Any idiot» comment could mean «I cannot judge the artist’s general intelligence level from this work». The «Even a monkey» comment could mean «The work does not even include any evidence of cognitive or behavioral abilities unique to our species of primate».

Interpreted from a signaling theory viewpoint, such comments are not stupid. Most people want to be able to interpret works of art as indicators of the artist’s skill and creativity. Certain styles of art make this difficult to do. People feel frustrated. They have efficient psychological adaptations for making attributions about the artist’s fitness given their work, but some genres of modern art prevent those adaptations from working naturally. Having paid the museum’s admission fee to see good art, they are instead confronted with works that seem specifically designed to undermine judgments about quality.

From the viewpoint of any normal living individual, all of one’s past survival attempts have succeeded, whereas most of one’s past courtship attempts have failed.

Sexual selection usually behaves like an insanely greedy tabloid newspaper editor who deletes all news and leaves only advertisements. In human evolution, it is as if the editor suddenly recognized a niche market for news in a few big-brained readers. She told all her reporters she wanted wall-to-wall news, but she never bothered to set up a fact-checking department. Human ideology is the result: a tabloid concoction of religious conviction, political idealism, urban myth, tribal myth, wishful thinking, memorable anecdote, and pseudo-science.

Ecologists have long understood that the typical interaction between any two individuals or species is neither competition nor cooperation, but neutralism. Neutralism means apathy: the animals just ignore each other. If their paths threaten to cross, they get out of each other’s way Anything else usually takes too much energy. Being nasty has costs, and being nice has costs, and animals evolve to avoid costs whenever possible. This is why watching wild animals interact is usually like watching preoccupied commuters trying to get to work without bumping into one another, rather than watching a John Woo action film with a triple-figure body count.

Apathy is nature’s norm.

Every hundred dollars we spend on luxuries could probably have saved a sick child from death somewhere in the developing world if we had donated it to the appropriate charity. The ten-thousand-dollar premium that distinguishes a sport utility vehicle from an ordinary automobile probably cost India a hundred dead children. We may pretend that it did not, but our self-justifications are no comfort to the dead. Perhaps if we imagined a hundred hungry ghosts haunting every luxury vehicle, runaway consumerism would lose some of its sexual appeal. While designer labels advertise only our wealth, the badges of charity advertise both our wealth and our kindness. As it is, the car manufacturers can afford better advertising than the needy children, which is why our instincts for display have been directed more toward consumerism than toward charity.

A classic symptom of paranoid schizophrenia is the belief that alien beings sometimes transmit their thoughts to us through invisible waves that influence our behavior. But every professor of linguistics knows that all ordinary people routinely transmit their thoughts to us through invisible waves that influence our behavior. The linguistics professors sound even more paranoid than the schizophrenics, but they simply have a greater respect for language. Most schizophrenics, like most other people, take language for granted, whereas language researchers recognize it as a signaling system of almost miraculous power and efficiency.

Given a strict male-display, female-choice mating system, we should expect female superiority in language comprehension and male superiority in language production. For example, females should recognize more words, but males should use a larger proportion of their vocabulary in courtship, biasing their speech towards rarer, more exotic words. In this simple picture, more women might understand what «azure» really means (so they can accurately judge male word use), but more men might actually speak the word «azure» in conversation (even if they think it means «vermilion»). Standard vocabulary tests measure only comprehension of word meaning, not the ability to produce impressive synonyms during courtship. Reading comprehension questions are more common than creative writing tests. Women are faster readers and buy more books, but most books are written by men.

Evolution’s job is to motivate us, not to satisfy us.

Among competent professionals in any field, there appears to be a fairly constant probability of success in any given endeavor. Simonton’s data show that excellent composers do not produce a higher proportion of excellent music than good composers — they simply produce a higher total number of works. People who achieve extreme success in any creative field are almost always extremely prolific.

Evolution may be heartless, but it is not humorless.

By viewing human evolution as a romantic comedy, we might understand not only our creative capacities for producing witty novelties, but also our ability to reinvent ourselves with each new sexual relationship. People act differently when they’re in love with different people. We tend to match our expressed interests and preferences to those of a desired individual. One develops a crush on a mountain-climber, and suddenly feels drawn to the sublime solitude of the Alps. One dates a jazz musician, and feels prone to sell one’s now puerile-seeming heavy metal albums. Should an otherwise perfect lover confide her secret belief in the healing power of crystals, one may find yesterday’s sneering skepticism about such nonsense replaced by a sudden open-mindedness, a certain generosity of faith that must have lain dormant all these years. In courtship, we work our way into roles that we think will prove attractive.

Chimpanzees have some capacities for «tactical deception,» for pretending to do something other than what they are really doing. But they cannot pretend to be someone other than who they are. Sexual courtship may have been the arena in which we evolved the capacity for dramatic role-playing. With each new lover, we experience a shift in image and identity. These shifts are rarely as dramatic as the changes of sexual personae adopted by David Bowie or Madonna with each new album. But they are more profound. Often, we may find it difficult to relate to our former selves from previous romances. Events experienced by that former self, which seemed so vivid at the time, become locked away in a separate quadrant of memory’s labyrinth, accessible only if we happen to run into the former lover. Our minds undergo these sexual revolutions, reshaping themselves to each new lover like an advertising company dreaming up new campaigns for capturing new market niches.