Sexual evolution and human culture:



Fear of fitness indicators:

How to deal with our ideological anxieties

about the role of sexual selection

in the origins of human culture

Geoffrey F. Miller

Assistant Professor

Psychology, Logan Hall 160

University of New Mexico

Albuquerque, NM 87131-1161, USA

(505) 277-1967 (office voice/fax)

(505) 277-1394 (dept fax)

gfmiller@unm.edu



Published as:

Miller, G. F. (2003). Fear of fitness indicators: How to deal with our ideological anxieties about the role of sexual selection in the origins of human culture. In Being human: Proceedings of a conference sponsored by the Royal Society of New Zealand, pp. 65-79. Wellington, NZ: Royal Society of New Zealand, Miscellaneous series 63.

Running Head: Fear of fitness indicators

Introduction: Mental evolution through mate choice

The human mind evolved somehow. Yet it remains unclear what evolutionary selection pressures favored our large brains, our creative intelligence, and our unique capacities for language, art, music, humor, romantic love, and moral commitment. Following Herbert Spencer's misleading phrase 'the survival of the fittest', most theorists throughout the last 140 years have tried and failed to identify the 'survival value' of these capacities. How did they contribute to life on the Pleistocene savanna of Africa, in which our hominid ancestors evolved?

Most evolutionary thinking about human mental evolution has emphasized the “production” payoffs for creative intelligence: our ancestors could invent better tools, which allowed more effective hunting, gathering, and defense against predators and rival groups, thereby improving survival prospects. This production orientation fit well with 20th century social science’s post-Marxist emphasis on economics and technological progress as determinants of human history. It was easy to project such an orientation back into human prehistory.

However, in recent years, an increasing number of evolutionary thinkers have begun emphasizing sexual reproduction rather than economic production as the driving force behind the evolution of animal and human behavior. This innovation actually dates back to Darwin’s (1871) book The descent of man, and selection in relation to sex. Darwin argued that sexual selection (for reproduction) is distinct from natural selection (for survival), and that traits inexplicable in terms of 'survival value' can often be explained as ornaments for attracting sexual partners. Over time, discriminative mate choice results in the elaboration of any traits that are noticed and appreciated by the opposite sex, such as body size and symmetry, beautiful plumage, healthy skin and fur, energetic gait, creative song-production, or social dominance. Thus, mate choice can explain the evolution of the peacock’s tail, the nightingale’s song, the elk’s antlers, and, Darwin argued, human intelligence, music, and morality. Unfortunately, Darwin’s Victorian peers rejected his evidence for mate choice, and could not accept that animals possessed the capacities of perception, judgment, and discrimination necessary for mate choice to play a central role in evolution (Cronin, 1991). As a result, almost all of 20th century psychology, anthropology, neuroscience, and the humanities developed without recognizing any significant role for mate choice in human mental evolution.

The dramatic revival of sexual selection theory since about 1980 (Andersson, 1994) has confirmed the utility of Darwin's distinction between natural and sexual selection. Sexual selection often produces extravagant traits that have high costs and complexity, yet these traits are often unique to one species, and absent in closely-related species. For example, closely-related birds often display quite different plumage colors and patterns, and sing very different courtship songs. By contrast, natural selection for ecological utility tends to produce convergent evolution, where many lineages independently evolve the same, efficient, low-cost solutions to the same environmental problems – traits such as wings, eyes, teeth, claws, hearts, and lungs. Sexual selection theory’s revival has been so dramatic that scientific journals concerning the evolution of animal and human behavior are now dominated by research on mate choice and its effects. Yet this revival has gone largely unnoticed in mainstream psychology, neuroscience, and the social sciences, which still view 'survival of the fittest' as evolution's bottom line, and which therefore have trouble seeing any evolutionary rationale for those aspects of human nature most concerned with self-ornamentation, display, status, ideology, fashion, and aesthetics.

Darwin’s view of the human mind as a set of courtship adaptations can be extended and refined in the light of modern sexual selection theory, evolutionary psychology, and evolutionary anthropology. In my recent book The mating mind (Miller, 2000a), I argued that many of our most distinctive mental traits evolved through mutual mate choice, in both sexes, to advertise intelligence, creativity, moral character, and heritable fitness. Indeed, the human brain itself can be viewed as a sexual ornament, since it has most of the hallmarks of sexually-selected traits: it is unique among living primates, it has high metabolic costs and enormous complexity, and its capacities are conspicuously displayed during courtship (especially verbal courtship).

The fact that male and female brains are fairly similar is congruent with evidence that human mate choice is mutual, with males and females almost equally choosy about the mental traits of long- term sexual partners. Sex differences are a distinctive outcome of sexual selection, but sexual selection does not always produce sex differences. So far, much of evolutionary psychology has focused on sex differences in courtship behavior and mate choice (e.g. Buss, 1999), but sexual selection theory is equally applicable to conspicuous, costly, ornamental traits in humans that are displayed by both sexes when they are reproductively mature.

Human mental traits as fitness indicators

If our most distinctive mental capacities evolved through mate choice, then to understand human nature, we have to understand how mate choice shapes traits as courtship adaptations. In the last 15 years, there has been a scientific revolution in our understanding of this issue, and the revolution depends on a branch of evolutionary theory called “biological signaling theory”. Signaling theory reaches all the way from the deepest fundamentals of evolution – mutation, genetic variation, and selection – right up to the most complex manifestations of beauty in nature and human culture.

All species face the problem of “mutational meltdown” (Ridley, 2001): cosmic rays and copying errors are constantly introducing mutations into the genetic code. These mutations are almost always harmful, because a change in any gene in much more likely to disrupt the gene’s function than to improve it. Yet, without the rare beneficial mutation, evolution would never make any progress. Thus, any genetic code (e.g. DNA) capable of progressive evolution is also vulnerable to progressive degeneration through mutation.

Without a way to “purge” harmful mutations from its genes, every species would eventually lose its ability to survive and reproduce effectively in its environment – it would suffer a mutational meltdown. In fact, many species that give up sexual reproduction in favor of non-sexual reproduction suffer precisely this fate: they almost always go extinct within a million years (Ridley, 2001). This reasoning has led many biologists to the view that sexual reproduction itself may have evolved as a way to purge harmful mutations (e.g. Atmar, 1991; Kondrashov, 1988; Michod, 1995; Michod & Hasson, 1990).

How can sex get rid of mutations? Mate choice can discriminate against individuals whose bodies and behaviors reveal a high “mutation load”. If an animal is showing poor health, poor coordination, and poor intelligence, this may because it is carrying a higher than average number of harmful mutations. A choosy animal would do well to avoid mating with such an unfit individual, lest its offspring inherit a similarly high number of mutations. Therefore, traits that happen to reveal mutation load more accurately than other traits (e.g. through more complex development that requires the interaction of more genes) will tend to be favored in mate choice. Under sexual selection, such traits will tend to grow ever larger, costlier, and more complex, so they function as ever more reliable indicators of good genes. Insofar as genetic quality implies expected evolutionary fitness, these sexually-selected traits could be called 'fitness indicators' (Andersson, 1994; Grafen, 1990; Johnstone, 1995; Michod & Hasson, 1990; Rowe & Houle, 1996; Zahavi & Zahavi, 1997).

Examples of fitness indicators are ubiquitous, because almost every sexually reproducing species has one or more, in at least one sex. The classic Darwinian examples of fitness indicators are extravagant ornaments such as the peacock’s tail (Darwin, 1871; Cronin, 1991). Recent research has shown that the quality of many such ornaments actually conveys reliable information about an individual’s general health, fitness, and genetic quality. This fitness-indicating function appears to hold true not only for peacock tails (Manning & Hartley, 1991; Moller & Petrie, 2002; Petrie, 1994), but for a very wide range of otherwise puzzling traits in many species, including:

• the length of eye-stalks in stalk-eyed flies (Hingle, Fowler, & Pomiankowski, 2001; Wilkinson, Presgraves, & Crymes, 1998),

• the amount of orange-red caretenoid pigment in guppy tails (Gong & Gibson, 1996; Kodric-Brown, 1985; Nicoletto, 1991),

• the symmetry of tail streamers in barn swallows (Moller, 1994),

• the rate of abdomen-drumming by wolf spiders (Kotiaho, 2000),

• the energetic intensity of copulation in a species of highly promiscuous beetle (Psilothrix viridicoeruleus) (Shuker et al., 2002),

• the size of the penis bone in bats (Hosken et al., 2001)

• the length and complexity of bird song in aquatic warblers (Catchpole & Leisler, 1996),

• the length and loudness of mating songs by gibbons (Colinshaw, 1996; Geissman, 2000), and

• the precision of song repetition in humpback whales (Chu & Harcourt, 1986; Miller, Biassoni, & Samuels, 2000; Noad, Cato, & Bryden, 2000; Payne, 2000).

Human bodies are full of reliable fitness indicators. Male human beards, penises, and upper-body muscles, and female breasts, buttocks, and orgasmic capacities, show evidence of having evolved through sexual selection (Dixson et al., 2003; Dixson, 1998; Etcoff, 1999; Miller, 2000a). There are also some traits that do not show large sex differences, such as long head hair, hairless skin, highly expressive faces, and full lips, that function as sexual attractants in our species (Langlois et al., 2000). These fleshy fitness indicators don't fossilize, and so have been neglected in studies of human evolution. However, all these traits are valued in modern mate choice, are displayed during courtship, and are mostly unique to humans. Also, the sexually differentiated traits (male beards, penises, and muscles, and female breasts and buttocks) develop fully only during puberty, in time for sexual attraction.

Human brains make particularly good fitness indicators because their growth depends on about half the genes in the genome, thereby summarizing a huge amount of information about mutation load (Miller, 2000a,b,c; Miller & Todd, 1998; also see Madden, 2001). Brains are also good indicators of nutritional state and general health, because they have such high energetic costs, constituting only 2% of body weight, but consuming over 25% of adult metabolic energy (60% in infancy). Indeed, the brain requires so much glucose that experimentally induced hypoglycemia can dramatically lower cognitive ability (McCrimmon, Deary, & Frier, 1997; Sommerfield, Deary, & McAulay, 2003). Moreover, the more important brains became during primate evolution (for whatever reason), the more incentive mate choice would have had to focus on specific indicators of brain quality (i.e. mental fitness as distinct from physical fitness).

Recent genetic analyses suggest that at least 1.6 harmful new mutations per individual per generation have been arising in our lineage for the last several million years (Eyre-Walker & Keightley, 1999; Crow, 1999). This probably exceeds the mutation rate that natural selection could contain in the absence of sexual selection for genetic quality. Without mate choice for fitness indicators, we would have suffered a mutational meltdown long ago.

What is the evidence that good brains and good minds are really sexually attractive in our species? Isn’t the putative attractiveness of creative intelligence just a conceit of the educated classes? Cross-cultural research on human mate choice suggests not. For example, in David Buss’s (1989) study of mate choice in 37 cultures across 5 continents around the world, five out of the top seven traits most desired by both men and women were psychological rather than physical traits. These psychological traits included kindness (rated #1 by both sexes), intelligence (rated #2 by both sexes), exciting personality, adaptability, and creativity. The only physical traits to make the top seven were physical health and physical attractiveness. Purely sociological or economic traits (such as social class or wealth) did not feature prominently in self-reported mate preferences in either sex of any culture. There is abundant evidence now for the importance in human mate choice of creative intelligence (e.g. Kanezawa, 2000; Li et al., 2002; Lynn et al., 2002; Miller, 1999a, 2000c; Reynolds & Gifford, 2001; Zebrowitz et al., 2002; Zechner et al., 2001) and kindness (e.g. Dessalles, 1998; Goldberg, 1995; Kelly & Dunbar, 2001; Johnson, 1996;

From fitness indicators to human culture

What do fitness indicators have to do with human culture? The biological signaling theory that explains naturally evolved fitness indicators is remarkably similar to the theory of conspicuous consumption developed by Thorstein Veblen (1899) to explain extravagant culturally invented luxuries (Miller, 1999). Highly fit animals show off their genetic quality by growing costly, precisely formed ornaments that their lower-fitness rivals cannot afford or imitate. Likewise, wealthy humans show off their pecuniary prominence by buying costly, precisely formed luxuries that their poorer rivals cannot afford or imitate. Indeed, the 20th century saw a parallel but largely independent development of signaling theory in biology (to explain costly sexual ornaments – e.g. Johnstone, 1995; Zahavi & Zahavi, 1997), in economics (to explain costly, conspicuous advertising and marketing efforts by corporations – e.g. Frank, 1999; Hellofs & Jacobson, 1999; Kirmani & Rao, 2000), and in sociology (to explain costly, conspicuous badges of social status – e.g. Veblen, 1899; Packard, 1960; Bourdieu, 1987; Illouz, 1997; Neiman, 1997; Gagnier, 2001).

How deep do the parallels go between these three strands of research – biological signaling theory, economic signaling theory, and sociological signaling theory? A skeptic might accept that the basic logic of costly advertisement may be the same, but argue that the functions of human economic and social-class signaling must be quite different from the fitness-indicator function of sexual ornaments in other animals. That is, we may display our wealth and status not to attract sexual partners, but to do something else. This view maintains the comfortable division between the animal world of genes, traits, and sex, and the human world of culture, ideology, and money.

However, I think the reasonable default view is that our wealth-displays and status-displays serve much the same mate-attracting and mate-retaining functions as the fitness-displays of other species. One way to see the potential overlap of functions is to consider in more detail the typical features that are shared by biological fitness indicators and human cultural displays such as art, music, and story-telling.

Conspicuous cost and conspicuous precision in fitness indicators

Fitness indicators often look rather different from standard naturally selected adaptations that solve standard survival problems. The evolved function of indicators is basically to advertise an individual’s fitness to other individuals. The only way to do this reliably is to grow a trait, or to emit a behavior, that a lower-fitness rival could not produce in such a high-quality form. Thus, fitness can be advertised according to several overlapping principles:

• Do something that a lower-fitness rival could not afford to do – in terms of time, energy, resources, or risk.

• Do something that would make your mutations, health problems, and psychopathologies very conspicuous

• Do something that requires special virtuosity to overcome some difficulty

• Do something that is very hard to do well, and very easy to do badly

Any fitness indicator that was easy to “fake” – such that a low-fitness individual could produce a high-quality version of the trait – would no longer be attended to by other animals, because it would no longer convey reliable information (Grafen, 1990; Zahavi & Zahavi, 1997). Thus, fitness indicators must be hard to fake in order to be reliable, and in order to remain evolutionarily relevant. The relevant evolutionary slogan is not “survival of the fittest”, but “truth in advertising”. There seem to be two major features that can make fitness indicators harder to fake: conspicuous cost and conspicuous precision.

Conspicuous cost. Low-fitness individuals cannot afford high-cost indicators, because they have a smaller budget of available time, energy, or resources, and must devote a higher proportion of their budget to basic survival needs (Johnstone, 1995; Zahavi & Zahavi, 1997). They cannot afford the luxury of high-quality sexual ornamentation. Often, sexual ornamentation requires high growth costs (e.g. energy and resources to produce a peacock’s tail, an elk’s antlers, or a human’s brain), high maintenance costs (e.g. preening, grooming, practice), and high repair costs (e.g. annual regrowth of moulted plumage, rewiring of brain areas injured by violence or stroke).

Conspicuous precision. Low-fitness indicators cannot manage to grow their bodies or brains with sufficient precision that they can display high-quality ornaments. Imprecise growth results in asymmetric, irregular, and unevenly colored ornaments. For example, animals with higher mutation loads tend to grow less symmetric bodies and ornaments, because the mutations interfere with the precision of right versus left side body growth (Gangestad & Thornhill, 1997; Moller & Swaddle, 1998; Thornhill, 1998). Also, humans with higher mutation loads tend to grow brains that show various anatomical and functional abnormalities, resulting in lower intelligence and higher rates of psychopathology (Yeo, 1999; Yeo et al., 1999).

The most common forms of conspicuous precision in sexual ornamentation seem to be: symmetry, averageness, the precise repetition of complex motifs, and the precise imitation of external phenomena. Human facial beauty for example involves the first two: faces are rated as most beautiful when they are bilaterally symmetrical and when they are close to the statistical average form for a human face (Etcoff, 1999; Langlois et al., 2000). By contrast, much of human culture involves the precise repetition of complex motifs (e.g. ornamental motifs in visual art, rhythm in music, movements in dance – see Gombrich, 1979; Zahavi, 1978) and the precise imitation of external phenomena (e.g. representational accuracy in art, accurate depiction of human nature in songs and novels, concordance criteria of truth in mental models of the world and scientific theories – see Gombrich, 1977; Miller, 2000a, 2001). Yet, repetition and mimesis are not uniquely human principles of fitness-display: humpback whale show off their fitness through the precise repetition of 30-minute whale songs to attract mates, and nightingales show off their fitness through the precise imitation of sounds made by other species.

From this fitness-indicator viewpoint, virtuosity is much more important than novelty in human cultural displays. Virtuosity is universally admired in every craft from every culture (Boas, 1955; Gombrich, 1977, 1979; Turner, 1992). In fact, the term “art” is used as an honorific term to identify almost any product of human behavior that is created with skill and attention that goes beyond the pragmatically necessary, that is “made special” in some way (Dissanayake, 1992) – i.e. that follows the logic of signaling theory. Whether in the geometric art of M. C. Esher, the complex wood carvings of Maori peoples, or the prehistoric cave paintings of Lascaux and Altamira, the ability to repeat complex motifs with precision, consistency, and skill is taken as a sign of expertise, and is considered “beautiful”. Indeed, Kohn and Mithen (1999) have even proposed that the evolution of tool-making ability in human evolution was driven in part by sexual selection favoring capacities to create large, symmetric, beautiful hand-axes.

The ideological problems with the fitness indicator theory of human evolution

The argument thus far has been, roughly:

• Some of our most distinctive mental traits (e.g. art, music, language, creativity, ideology) are hard to explain as survival adaptations

• Darwin’s process of sexual selection through mate choice can explain many traits in many species that are hard to explain as survival adaptations

• Sexual selection often produces “fitness indicators” – traits that advertise an individual’s genetic quality through conspicuous cost and precision

• Fitness indicators follow the “truth in advertising” logic of biological signaling theory, which is similar to theories of wealth-signaling and product-quality-signaling in economics, and theories of social-status-signaling in sociology

• Some human mental traits and cultural forms have already been analyzed as wealth-signals and status-signals, so it is not a great reach to consider them as possible fitness-signals as well

• Some human mental traits and cultural forms bear other hallmarks of sexual selection, so they may serve the same biological function (mate-attraction) as fitness-signals in other species

In response to longer versions of this argument (e.g. reviews of my book The mating mind, and questions after my public talks), two reactions are often voiced: “So what?” and “Oh no!”. The “So what?” reaction I deal with at much greater length in the book itself. My focus for the rest of the paper here is on the “Oh no!” reaction. Often, this reaction arises from concerns about the political, religious, and ideological implications of this fitness-indicator view of human mental evolution and of human culture.

Basically, the idea that the human mind evolved as a bundle of fitness indicators does not sit comfortably with contemporary views of human nature and human society. In fact, it violates at least six core values commonly accepted in modern society:

1. Fitness variation vs. human equality. Fitness indicators are designed by evolution to reveal individual differences in general intelligence, health, fitness, and genetic quality. They maximize apparent differences between people both objectively (by amplifying small differences in genetic quality into big differences in apparent physical and psychological attractiveness), and subjectively (by shaping our social-perception instincts to pay a great deal of attention to fitness indicators). This leads us to a virtual obsession with the minutiae of individual differences in our social interactions – not only in mate choice, but in our choices of friends, allies, co-workers, mentors, and leaders. Fitness indicators make all sorts of differences loom very large indeed, including psychological differences in intelligence, kindness, agreeableness, aggressiveness, conscientiousness, conservatism, neuroticism, psychoticism, extroversion, and ideology. Insofar as different ages, sexes, ethnic groups, and races may have somewhat different averages and degrees of variation in these traits, our obsession with differences is easily generalized from individuals to such groups, leading to various forms of ageism, sexism, ethnocentrism, and racism. Necessarily, this difference-obsession also tends to eclipse our awareness of what we humans have in common – and it is precisely our common human nature that is the basis for the classical liberal enlightenment concepts such as “human rights”, “equality before the law”, “universal suffrage”, and “democracy”. Thus, a descriptive emphasis on the role of fitness indicators in human evolution appears to sit very uncomfortably with a normative respect for human equality.

2. Judging people by their indicators vs. by their character. A related problem is that the components of genetic quality that are advertised by fitness indicators can seem quite impersonal. If intelligence, creativity, sense of humor, and even kindness are simply reflections of how many mutation-free genes we carry, then human dignity may seem reducible to DNA. Equally, when we think we are judging people by unique, deeply personal qualities, fitness indicator theory suggests we are really paying attention to species-typical indicators that can be arrayed along dimensions of superiority vs. inferiority. This viewpoint seems to leave little room for developing a personal identity apart from one’s heritable indicators, or for being judged by others as anything other than an advertisement for one’s genes.

3. Mate choice for good genes vs. romantic love. This is really a special case of the above point, but it is an especially important, emotionally charged special case. The fitness indicator view suggests that sexual attraction is largely a matter of integrating physical and psychological cues of genetic quality, and finding the highest-fitness partner who will actually reciprocate one’s affection. By identifying the major fitness indicators, the ways in which we weigh and integrate them, and the ways in which we search for mates from the pool of possibilities (e.g. Miller & Todd, 1998; Todd & Miller, 1999), evolutionary psychology works to demystify human love and romance. Many of us do not want love demystified, because the romantic commitments entailed by true love do not seem capable of surviving such demystification. In short, we like to pretend that there was only one predestined “true love” out there for us, and that we made no comparative judgments concerning the relative fitness of our true love and other potential mates. Indeed, putting one’s marriage into the arena of comparative judgment risks undermining the emotional commitments that keep one from wandering into infidelity and divorce. Thus, fitness indicator theory seems hostile to the mythology of romantic love, and to the emotional demands of marriage.

4. Heritable fitness vs. parental and cultural influences on human development. A major discovery in sexual selection research has been that many aspects of general fitness are heritable. Indeed, the most common evolutionary rationale for mate choice may be that it allows individual to get better genes for their offspring. Moreover, the better a fitness indicator works as a cue of general genetic quality, the more heritable will be individual differences in the quality of that indicator. This sounds fine in the abstract, but it becomes problematic when we start viewing as fitness indicators many human mental traits – such as general intelligence, language ability, sense of humor, artistic ability, musical ability, kindness, and altruism. If intelligence is a good fitness indicator, then intelligence is probably highly heritable – and all the behavior genetics research suggests that it is (e.g. Plomin et al., 2001). Before the rise of fitness indicator theory, it was possible to argue that heritable traits must not be that important, because selection would have long ago eliminated any heritable variation in traits that really mattered in survival or reproduction (see Miller, 2000b,c). However, fitness indicator theory points out that some sexually-selected traits can remain both extremely important in social and sexual life, and very highly heritable (Miller, 2000c; Rowe & Houle, 1996). Thus, heritability can no longer be taken as a symptom of evolutionary irrelevance. This leaves the “nature vs. nurture” debate in a very unbalanced state, with behavior genetics research showing “nature” (one’s genotype) looking ever more powerful and socially important, leaving “nurture” (one’s shared family environment in childhood) looking impotent. That is, the quality of parenting and early family life simply doesn’t influence how an individual will turn out as an adult, except in cases of extreme abuse or neglect. Thus, a descriptive emphasis on the role of fitness indicators in human evolution seems to fit very poorly with a normative respect for the importance of parenting and culture in individual human development. We want parenting to be important to justify our efforts and attentiveness as parents, but fitness indicator theory combined with behavior genetics findings shows that this desire for parental relevance is largely futile.

5. Narcissistic self-display vs. civilized humility. Loudly advertising one’s fitness violates our values of humility, decorum, and tact. Fitness indicator theory views self-display as central to human evolution, so could be construed as providing an excuse for all manner of narcissistic showing-off – bragging, strutting, consuming conspicuous luxuries, and derogating one’s less extroverted rivals. Yet many cultural norms have developed precisely to restrain runaway showing-off by rivals – especially young, single, male rivals – within society. The law itself can be viewed largely as an attempt by older, mated men to minimize the anti-social effects of runaway status competition by young, single men. These anti-social effects range from noise pollution (e.g. playing rock or rap music at high volume from one’s car) to lethal violence (e.g. the tendency of accidental slights to escalate into mortal combat among aggressive young men). If fitness indicator theory provides a clear, coherent rationale for such showing-off (i.e. it has high reproductive payoffs), it becomes harder for older do-gooders to argue that all such showing-off is irrational and contrary to the true interests of the perpetrators. Indeed, fitness indicator theory appears to give the perpetrators an ironclad excuse for all manner of loud, aggressive, self-display – fitness signaling as a basic human right, perhaps. Thus, highlighting the evolutionary payoffs to fitness signaling seems to conflict with our desire to justify social norms against narcissistic self-display and showing-off.

6. Fitness signaling vs. transcendental cultural meaning. Perhaps the hardest thing to accept about fitness indicator theory is what it does to the content of human cultural creations, such as works of art, music, literature, and religious inspiration. It suggests that the content of such works is a peripheral and somewhat incidental feature of the work’s function as a fitness indicator. For indicators, form is closely tied to function: indicators are most informative when they display easy-to-assess “surface” qualities such as high cost, symmetry, regularity of design, and accuracy of mimesis. To the sexual selection theorist, the visual themes of a painting may be less important than the monetary cost of the pigments used, the amount of time and energy invested by the painter, and the correlation between the painter’s manifest skill level and his or her mutation load. Fitness indicator theory puts these “superficial” features at the heart of human cultural effort, and relegates thematic content to the periphery, as just another form of cognitive ornamentation. This viewpoint threatens the Romantic-era ideologies of transcendence, genius, inspiration, salvation, and social utility that remain the major popular justification for the arts, the humanities, and religion. Thus, fitness indicator theory seems corrosive to cultural content, symbolism, and social values. It seems nihilistic to propose that our capacities for language, art, and music evolved to proclaim just one message that has been repeated loudly and insistently for thousands of generations: “I am fit, my genes are good, mate with me”.

Resolving the ideological problems with fitness indicator theory

How is it possible for one biological concept to affront so many of our fundamental values? It seems quite astounding that a scientific idea should so consistently fall on the wrong side of the ideological fence. I think it is no coincidence. Look at it this way: our human norms and values developed as reactions to patterns of natural human behavior that we decided should be discouraged. If a great deal of human behavior consists of advertising one’s fitness, and if many ways of doing that impose social costs on others, and if moral norms develop to minimize social costs, then a lot of moral norms should be aimed directly against the irresponsible use of fitness indicators. For example:

• We teach equality to fight arrogance and dominance, and to limit the subjective distress caused by inequality

• We teach that everyone has a unique identity apart from his or her indicators, to promote sympathy in our social and sexual relationships

• We teach romantic love to limit the callousness with which we judge potential mates, to limit mate-switching and infidelity, and to stabilize families

• We teach that nurture is important, to remind parents to care about the subjective well-being of their children

• We teach humility to limit obnoxious showing-off and fitness-displaying

• We teach that cultural works have deep, socially important meanings, to promote the production of cultural works that really may have such meanings, rather than the superficial signs of high fitness.

These social norms do not just fall randomly from the sky. They emerged as moral instincts and cultural inventions to combat the excesses of sexual self-advertisement and sexual competition. Our moral aversion to fitness indicators may tempt us to reject them as an important part of sexual selection. But if we reject them, then it is hard to see how our moral norms evolved in the first place. It is possible, perhaps even necessary, to admit that much of human behavior evolved to advertise fitness, while simultaneously realizing that the essence of wisdom and morality is not to take our fitness indicators too seriously. This is not to say that our capacities for wisdom and morality are cultural inventions that liberate us from the imperatives of our genes. Our moral instincts may be just another set of evolved adaptations. It is not question of “us” over-riding our genetic predispositions, but of using one set of predispositions to over-rule others – just as our evolved desire to preserve our looks can over-ride our evolved tastes for fats and sugars.

A major prediction of fitness indicator theory is that in every culture, and perhaps in every individual, there should be a dynamic balance between our mating instincts for fitness-display, and our moral instincts for restraining the social and personal costs of runaway fitness-display and sexual competition. In many societies, certain groups of people tend to become advocates for one side or the other. Often, it seems to me that the advocacy groups break down as follows – on average, in most places and times:

Against runaway fitness signaling: For runaway fitness signaling:

Women Men

Old folks Young folks

Conservatives Liberals

Fascists, Communists Libertarians

Marxism Consumerism

The bourgeoisie The bohemians

Monotheists Pagans

Obsessive-compulsives, Paranoids Narcissists, Psychopaths

Group-minded do-gooders Irresponsible individualists

Economists Marketers, Advertisers

Ecologists Sexual selection theorists

Sociologists Socialites

Volkswagen-drivers Porsches-drivers

Immanuel Kant Friedrich Nietzsche

Al Gore Bill Clinton

Tipper Gore Britney Spears

If this amateur sociology is even vaguely correct, then we need not worry that the advocates of fitness indicator theory will cause any permanent injury to the social fabric. There will remain a dynamic ideological balance between those in favor of runaway fitness signaling and those opposed to it, as long as we have a demographically balanced society.

Some social benefits of the fitness indicator view

Of course, one is not likely to win over many hearts and minds by pointing out that a scientific theory is not quite as horribly unsettling as it first appears. One must offer some positive social benefits of adopting the new view. I believe there are several such benefits to emphasizing the role of sexual selection in human mental evolution. These benefits seem to fall into five categories: intellectual, educational, economic, aesthetic, and spiritual.

Intellectual benefits. To scientists, the intellectual, theoretical, and empirical benefits of a new viewpoint are paramount – indeed, other ideological considerations are considered irrelevant at best, and corrosive at worst. In most of my other writings, my focus has been on the purely scientific benefits of fitness indicator theory as a framework for understanding human nature. In this paper, my focus is on the non-scientific, “ideological” issues, so I will just mention one major intellectual payoff offered by the fitness indicator viewpoint: “consilience” (Wilson, 1999), which is the potential to integrate seamlessly the biological and social sciences with the arts and humanities (Miller, 2000a). Signaling theory offers a common language and functionalist framework that spans the realms of the biological, the economic, and the cultural. Of course, the proof is in the pudding, and it remains to be seen whether this potential for consilience is fulfilled over the coming decades of research.

Educational benefits. Ever since Darwin, most theories of mental evolution have stressed the economic and technological payoffs for human creative intelligence. This can easily lead to a sort of nerd’s eye view of public education, in which business management and computer programming are viewed as the pinnacles of human cognitive achievement, and in which art, music, sports, social life, and sexual education can be marginalized as “extra-curricular activities”. The fitness indicator view inverts this cognitive hierarchy by pointing out that economic success and technological invention are just two among many natural ways that individuals advertise their fitness – and they are not even considered the most sexually attractive or romantic ways by most people. If educational policy recognized that training individuals to be socially and sexually successful was at least as important to their subjective well-being and quality of life as training them to be technically proficient at some employable skill, then fitness indicator theory would offer a strong argument for putting the arts and humanities at the core of the curriculum. At the moment, the interests of corporate employers seem to dictate much of educational policy in many industrialized nation, and those interests typically demand that young humans spend thousands of hours learning frustrating, counter-intuitive, evolutionarily novel skills such as mathematics, word processing, and accounting. The corporate world is not much interested in promoting fitness-indicating skills that young people seems intrinsically motivated to learn and practice, which are socially and sexually rewarding, and which tap their naturally evolved cognitive abilities – such as art, music, story-telling, drama, natural history, humor, sports, and socializing. At the very least, fitness indicator theory can help educational policy-makers become less hypocritical and self-deceiving about whose interests are being served by current educational practices.

Economic benefits. Early theories of human evolution coincided with the peak of industrial capitalism based on heavy industry – the world of coal, oil, steel, railroads, automobiles, armaments, and factories. In this world, the economy seemed to be based upon the transformation of raw materials into physical tools, weapons, vehicles, and buildings. Materialism – whether Marxist or capitalist, dialectical or techno-scientific – seemed an appropriate way to describe how the world works and how the human brain evolved to understand that world. However, with the rise of sexual selection theory and fitness indicator theory, the world appears not so much a set of raw materials and physical products, as a system of signals, advertisements, status games, and socio-sexual transactions. This new view seems much better suited to understand the global 21st century economy as it is – a system that delivers service, entertainment, education, experience, and information – rather than as it was in the mid-19th century world of heavy industry. Indeed, without the fitness indicator perspective, it is very difficult to understand modern marketing phenomena, which are at the heart of modern business practice (Miller, 2000d,e; Saad & Gill, 2000). All successful contemporary businesses understand that profits arise not from commodifying their products (i.e. stripping them of brand identity, advertising associations, and fitness-signaling potential), but from ‘adding psychological value’ to their products by increasing their fitness-signaling, status-signaling, and identity-signaling potential (Frank, 1999; Klein, 2000; Twitchell, 1999). The fitness indicator view also helps us why status has become so dematerialized in advanced economies – why it is based much more on one’s experiences of education, travel, entertainment, and self-fulfillment, than on what physical products one owns (see Brooks, 2001; Conniff, 2002; Pine & Gilmore, 1999). By adopting the new signaling-based view of human mental evolution, it is much easier to see the connections between prehistoric life and post-industrial life, between fitness-signaling and status-signaling, between personal identity and brand identity, and between the social functions of products for consumers and the profitability of products for manufacturers and marketers.

Aesthetic benefits. Art theory and art criticism throughout the 20th century was dominated by the novelty-obsessed doctrines of Modernism, Post-modernism, and social-constructivism. This often led to the privileging of elite, often arcane forms of culture – whether the “high art” of the New York/London axis or the fashionably obscure forms of “pop culture” – over the ordinary folk arts enjoyed by most people across culture. Since folk arts everywhere tend to value virtuosity over novelty (Boas, 1955; Gombrich, 1977, 1979), clarity over obscurity, and pragmatic sexual signaling-power over theoretical “meaning”, this 20th century emphasis often left folk arts out in the cold. A major benefit of fitness indicator theory is that it puts folk art – ordinary ornamental and representational forms of visual display – back to the heart of aesthetic theory (Miller, 2000a, 2001). It gives art theorists and critics a richer new language for describing the forms of art and ornamentation that have been most popular and widely appreciated across cultures and across history. The fitness indicator perspective makes it as easy to talk about the aesthetics of the Aeron office chair, the BMW 540i automobile, and the suburban tract mansion as it was for Modernist theorists to talk about Picasso, Pollock, and Pei. Also, it reconnects contemporary aesthetic theory to an alternative, non-Modernist intellectual tradition that runs from Aristotle through a long list of rather neglected biophilic theorists:

• Charles Darwin (1871),

• Friedrich Nietzsche (1883-1888/1968),

• Herbert Spencer (1890),

• Ernst Grosse (1897),

• Thorstein Veblen (1899, 1914),

• Yrjö Hirn (1900),

• Frans Boas (1955),

• Pearl Binder (1958),

• Desmond Morris (1962, 1985),

• Thomas Munro (1963),

• Ernst Gombrich (1977, 1979),

• Amotz Zahavi (1978),

• Richard Dawkins (1982),

• Pierre Bourdieu (1987),

• Frederick Turner (1992, 1995),

• Denis Dutton (1983), and

• George Hershey (1996, 1999).

This tradition of biophilic aesthetics overlaps perfectly with modern evolutionary psychology research on the beauty of human faces and bodies (e.g. Etcoff, 1999; Thornhill, 1998).

Spiritual benefits. I can’t stand the word “spiritual”, and I have no idea what it really means, but some people seem to think it’s important. Many such people seem highly motivated to understand their place in the cosmos, and to feel the sense of oceanic oneness with the universe described so well by William James (1902) in The varieties of religious experience. The fitness indicator view might be useful in promoting such feelings, insofar as it:

• views our most distinctive human abilities and aspirations as natural outgrowths of the biological world

• connects the most abstract forms of cognition and culture (the “head”) to the embodied functions of sexual reproduction and social interaction (the “heart”)

• reconciles our sense of personal identity and uniqueness to our function as conduits of genetic knowledge from the distant past to the distant future

In these ways, the fitness indicator view is profoundly anti-reductionist and anti-materialist, while still being scientifically precise, testable, empirically well-supported, and theoretically fruitful.

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