1.         Peacocks’ elaborate tail feathers are a result of sexual selection.  When a peahen is choosing a mate, she must select the peacock that will provide her chicks with the best genes. However, she cannot literally check each peacock’s genotype1; she must choose based on their phenotypes. This can be problematic, because not all genetic information is revealed by an organism’s appearance. For example, a harmful recessive mutation may be invisible in a peacock’s phenotype, but it could be expressed in the peafowl chicks if the peahen carries the same recessive mutation. Peacocks’ elaborate tail feathers help solve this problem by acting as fitness indicators. Because the tails feathers are so complex, they depend on the effective interaction of many genes. Also, only healthy peacocks can afford the resources to grow and maintain such an ornamental tail. As a result, peahens can tell a lot about a peacock’s fitness by examining its tail. 

            In the ancestral species that gave rise to peafowl, peahens that preferred to mate with healthy, long-tailed males produced more offspring with fewer harmful mutations. Their male offspring were likely to inherit the genes for long tails, and their daughters were likely to prefer long-tailed males. As this pattern continued, peafowl carrying the gene for long tails and the gene for a preference for long tails continued to mate with each other. The average tail length increased with each generation. Eventually, this process gave rise to the elaborate peacock tails that exist today.

            Later in the reading, Miller points out that as a species, it would be in peafowl’s best interests not to waste energy growing fancy tails. However, at the individual level, there is incentive for peahens to choose fancy-tailed peacocks and for peacocks to grow fancy tails. Since natural selection occurs at the level of the individual rather than the species, the incentive towards elaborate tails wins out.


2. Like the tail feathers of the peacock, the human mind evolved as a fitness indicator. Complicated brains are susceptible to being thrown off by even a small number of harmful mutations. Complex behaviors such as language and creativity are somewhat helpful to survival, but humans are much more creative and lingual than is necessary for survival alone. This implies that sexual selection played a role in the evolution of these abilities. Miller suggests that these abilities allow individuals to broadcast the quality of their genes to potential mates.


3. Miller points to our sense of beauty, the value we place on creativity, and the complexity of our verbal communications as evidence that the human mind is sexually selected. The art that humans tend to find most beautiful is the art whose production required an evolutionarily fit artist. For example, the creation of most beautiful art requires manual skill, creativity, and the procurement of rare materials.2 It makes sense that we are attracted to creativity, because creativity correlates highly with overall intelligence, which is heritable. Vocabulary size also correlates highly with overall intelligence. We have hugely redundant vocabularies; the average person knows 60,000 words, but basic communication can take place with only 850. Language, because it allows us to communicate our thoughts and mental states in such detail, makes the brain an especially effective fitness indicator. After the development of complex language, many more of our mental characteristics began to be acted upon by sexual selection.


4. Of all modes of human communication, music is unrivaled in its universal appeal and its ability to tap into emotion. Poetry comes close, but it is more of an acquired taste. There are people who dislike all poetry3, but I have never heard of anyone who hated all music. Rock stars produce music that is especially accessible to a wide range of audiences. As a result, they gain large followings. Humans are attracted to power, fame, and large crowds of overexcited fans of the opposite gender. Hence, many male adolescents dream of becoming rock stars.


5.         I do think that Miller is correct in his assessment of artistic motivation. The impulse to create art and music is so universal that it must be rooted in our genes, and what is rooted that prominently in our genes must somehow be the product of natural selection. However, if natural selection from our environment was the only force encouraging creativity, we would not be creative to the degree that we are. Some level of creativity has practical survival benefits, but our tendency to create art and music goes far beyond this rudimentary level of “survival creativity.” Sexual selection is a reasonable alternate explanation for our artistic abilities.4

            Every time I study how another characteristic of humanity originates in natural selection, my first reaction seems to be a feeling of loss. Last year, for example, the human moral sense as a product of evolution took some getting used to. I don’t know quite what it is about explanation that seems so counter to meaningfulness5; I recognize that I am being irrational in my disappointment. After all, every aspect of humanity is the product of natural selection. Miller’s explanation of artistic motivation only makes music less meaningful to the extent that explaining friendship, generosity, or any other characteristic in terms of natural selection renders them meaningless. (Which I do not think is the case.) In addition, music’s “meaning” comes from its emotional appeal in the first place, not from its practical value. Whatever its origins, music remains an incredibly powerful mode of human expression and a vital source of community.

            One aspect of this excerpt that did strike me as sad was Miller’s suggestion that there is sexual dimorphism in creativity. I guess I always accepted the differences between the average male and the average female in terms of sheer physical strength. But in terms of mental skills, I never believed that there are significant gender differences. I always thought that the reason there are so few prominent female philosophers, composers, painters, etc. was merely a lack of opportunity. But Miller suggests that creativity is like a peacock’s tail, and I can’t help but think how drab and brown peahens are. Would there have been equal selective pressure on both males and females to be creative and have high rates of cultural production? Maybe it wouldn’t have mattered; even if selective pressure acted more strongly on males than females, creativity might have spread evenly throughout the entire population. But Miller’s statistics imply that he does not believe this to be the case. Oddly, his statistics do not agree at all with the patterns I see at LHS, where humanities electives are overwhelmingly filled with females and math/physics/computer science classes are skewed the opposite way.6


6. Zahavi’s handicap principle says that for a sexually selected trait to be an effective fitness indicator, it must be costly to the organism. In other words, a reduction in an organism’s survival fitness can actually increase its reproductive fitness, because it shows that the organism is healthy and can afford the cost of its fitness indicators.


7. People like to show off their wealth. This tendency has the same evolutionary roots as peacock tails or human musicality; it originates in the need to show off one’s attractiveness as a mate. Ostentatious displays of wealth have the added benefit of establishing one’s power within a community, possibly intimidating individuals who otherwise would have represented competition. Abercrombie and Fitch shirts, because they are expensive, are a way to display wealth and to indicate that the wearer can afford to focus on items not necessary to survival.


8. Most of the people who buy automobiles after viewing commercials do not really need new cars. Instead, they are motivated by the prestige of a new vehicle. People enjoy flaunting their expensive cars for the same reason they enjoy wearing Abercrombie and Fitch shirts. Both these enjoyments originate in fitness indication and mate attraction. Subconsciously, seeing attractive women in automobile commercials makes men think that a new car will make them more attractive.7



1. But will modern technology soon allow humans to choose mates partly-based upon genetic analysis?  Will people start adding to their social profiles the possession of desirable genes and the absence of mutations?


2. Which has been true for thousands of years, though it suggests an alternate explanation is needed for what many view as less-skill-based modern art.  In fact, the intuitive revolt many feel against modern art may be further evidence for our evolved sense of what is “truly” artistic.


3. Most popular music is really a combination of mediocre poetry and mediocre music.  When divided and attended-to separately, the mediocrity becomes fairly apparent.  Yet somehow, the combination is very appealing.


4. I’m guessing for many, the very word “creativity” has an implicit uselessness.  These are people who express looks of disbelief when it is suggested creativity is involved in something like science or mathematics.


5. It may be cultural.  For example, when Watson beat everyone at Jeopardy, I’m sure the response of many was, “Well, it was just doing a bunch of computations” rather than, “Wow, what an amazing accomplishment of programmed cognition.”  And perhaps there’s an unconscious resistance to thinking of ourselves as just a part of the universe rather than superior to it.


6. Miller’s work is interesting, but it’s still very-much introductory, so I wouldn’t quickly couple it to capital-T truth.  Also, one must consider human traits along Gaussian curves.  For example, two curves could overlap so that, on average, men have a higher ability than women, but, because the Gaussian curve of women has a higher standard deviation, there are more women in the top quartile of that ability.  And there are all sorts of other factors at play: pressures to conform to gender-norms, different timelines of maturation of the two sexes, differences in competitiveness, etc, etc.


7. I should update this question.  Car commercials have become far less blunt in their advertising than, say, Axe body spray.