Beauty refers to aesthetic appearance. It is sexually attractive and important for social status. A study suggests that subjective beauty is regulated by structures of the brain associated with positive memories, whereas objective beauty may be mediated by the insula in the brain. Physical attractiveness strongly predicts initial romantic interest to the same degree in men and women. Humans judge beauty within less than a second and beauty is strongly related to perceived health, but not related to intelligence, academic performance, integrity, or concern for others which is known as the beauty-is-good stereotype, a certain kind of halo effect. People are fairly bad judging their perceived physical attractiveness, especially men.
Objective vs subjective[edit | edit source]
One can distinguish objective and subjective preferences for body shapes. Objective preferences are inherited, so everyone mostly agrees on them. Subjective preferences are acquired through emotional experience.
Objective beauty is mostly about mathematical/geometric simplicity, which includes symmetry, smoothness, averageness, repetitions and elegance. It has been proposed many animal brains have a natural preference for this because simplicity is easy to process, which is called the processing fluency theory of aesthetic pleasure.
An example may be that even blind men prefer women's elegant hourglass-shaped body, suggesting men are born with this aesthetic preference.
In many animals ornament can also be very complex rather than simple, e.g. the peacock tail, however this kind of ornament is still simple in that it consists of repeating patterns.
Evolution of beauty[edit | edit source]
The processing fluency hypothesis suggests that animal's preference for objective beauty as mathematical simplicity is a fluke of evolution, resulting from the actually useful preference for order and predictability. Due to this preference, animals tended to choose mathematically beautiful mates and hence species evolved to be beautiful (aesthetic sexual selection) and beauty became an important factor of sexual attraction. Some deep sea fish may be particularly ugly due to being blind.
Simple and elegant body shapes can, however, also result from optimizing resource efficiency or resilience. This explains why even blind animals and plants are often beautiful. Though, some flowers may have also evolved beauty and scents to be particularly salient to insects which spread their pollen. Similarly, many animals use beauty to conspicuously advertise themselves to the opposite sex. For this reason, human females use flowers as adornment to get men's attention since flowers happen to fulfill the same function. Attraction to secondary sexual characteristics generally increases fitness because seeking out the opposite sex is conductive for reproduction.
Feedback loops in sexual selection such as Fisherian runaway and sensory bias can explain why secondary sexual characteristics are overcomplicated and enlarged in some animals, and they can also explain the immense sexual attraction to very specific shapes (few millimeters of bone) despite them having barely any relevance for survival except "social survival". Runaway selection narrows or stabilizes preferences explaining millimeters of bone, uncanny valley and aversion to other races. Runaway selection also exaggerates preferences,which may explain phenomena such as women readily copulating with sexy men despite being coy otherwise, as well as love on first sight, oneitis and porn.
Another explanation for beauty is that it acts as an honest signal of e.g. health, mutational load and intelligence, can thus signal good genes overall. These two opposing views the Good Geners vs Fisherians lead to significant academic rivalry since the 1990s, but the good genes hypotheses has largely been refuted since. The relation between beauty to health and ability is only relevant for certain cases like disfigurement, certain syndromes and skin rashes and the like. Beauty and health are overall only weakly related (see correlations), but slight fitness advantages could have also initiated feedback loops in sexual selection.
Historically, parents have been heavily involved in their offspring's mate choices, so quite likely feedback loops in sexual aesthetic selection have also shaped parents to be choosy about looks (sexy grandchildren), and, due to the similarity of socializing with potential partners for their offspring with socializing in general, people have evolved to be choosy about looks of the people they socialize with, explaining why looks influence men's social status somewhat.
Beautiful behavior[edit | edit source]
Not just looks, but also behavior can be beautiful and sexually attractive, such as facial expressiveness, gait, physiognomy, tone and clarity of the voice, or more generally charisma. Analogously to objective beauty described above, beautiful behavior has elegance, confidence, poise, wit, i.e. it can be processed fluently, and also includes production of art, dancing, humor etc.
The opposite is awkwardness, lethargy, stuttering, violation of norms, autism, inappropriate laughter, delayed response, anxiety etc. Aesthetic sexual selection possibly played a role in the evolution of these behaviors, especially as they lack obvious survival value apart from being socially advantageous. Also, in some birds, fish and other species one can observe animals (especially male ones) competing in performance of complex behaviors (courtship display), which ranges from courtship dances to construction of aesthetically pleasing nest formations. In the same manner, higher human cognition has been suggested to have largely evolved by sexual selection as a "cognitive ornament".
The failure of any personality traits and intelligence to predict initial romantic interest in blind and semi-blind settings, however, suggests sexually selected beautiful behavior is limited to rather momentary, superficial and sub-personality behaviors such as facial expressions and, perhaps singing, dance movements, and overall smoothness and neurotypicality.
Male dancers of the Wodaabe African tribe (see video) are a clear example of men showing off sexual adaptations for facial expressiveness, fine control of facial muscles, glances, smiling, sense of style and adornment, singing, chanting, whistling, as well as the white of the eye (sclera), straight white teeth, all of which are possibly sexual/aesthetic adaptations. Wodaabes believe men who are not physically beautiful can make up for it with togu (game) and flirting with poetic speech patterns called sweet tongue, i.e. beautiful behavior. Such courtship performances have striking resemblance with modern day jestermaxxing and tindermaxxing. People on the autism spectrum often lack fine control of their facial muscles and have unfamiliar body movement.. Dance performances with rhythmic and rocking motions, delicate hand movements, and overall elegance, poise and coolness are seen in many indigenous cultures, so these behaviors are generally potential candidates for being primarily sexual adaptations as they evidently played an important role in mate selection for both men and women, as can be seen by women also being involved in dances, instead of just watching the males dance.
Correlations[edit | edit source]
Beauty is only slightly negatively related to criminality, and beauty is only very weakly related to intelligence, if at all. A recent meta study of 1,753 identical and fraternal twins and their siblings found no correlation between facial attractiveness and IQ, and suggested studies that previously found a weak correlation suffered from halo effect as they involved attractiveness ratings of acquaintances. The halo effect of attractiveness on perceived intelligence is pretty significant.
Beauty is also at most only weakly correlated with health. Science that purported a link between facial fluctuating asymmetry and health has been exposed as outright scientific fraud. A survey study by Henderson et al. (2015) summarized:
Contrary to the hypothesis that symmetry cues health, the largest study of facial asymmetry and health to date found no relationship between these variables. Researchers used data from a British cohort study of 4732 individuals and found that facial symmetry at age 15 was unrelated to longitudinal measures of childhood health, including measures of the proportion of childhood years spent unwell, average number of illness symptoms per year, and total number of infections.
Different aspects of beauty are also not inter-correlated, e.g. no correlation between attractive faces and attractive voices.
The waist-to-hip-ratio/fertility link is weak at best.
The relationship between health and mating success is weak, i.e. people select for physical attractiveness rather than health. Physical unattractiveness only correlates weakly with general health (r = .13, p < .001). See the figure on the right for predicted probabilities for various diseases, controlled for age, sex, race, income and parents' income. The causality is unclear. Ugliness could cause social exclusion, making them depressed which increases their blood pressure and causes other chronic diseases, or disease could be caused by the environment and the disease may reduce looks (e.g. eye circles and wrinkles), but "bad genes" (a general fitness factor) could also cause both ugliness and bad health.
Deeper male voice is not linked to immunocompetence even though women are strongly attracted to it. A deep voice in particular may mainly have the purpose of intimidating other men, i.e. intrasexual competition.
In summary, beauty in humans, which is mostly averageness, smoothness and symmetry, is not a certificate for health or ability. Even though deformities may slightly signal developmental instability, mutational load and autism, beauty mostly seems to be just ornament, i.e. its main biological purpose is to be sexually attractive. Runaway selection may explain our exaggerated preference for it, and why people undergo risks improving their looks by plastic surgeries.
See also[edit | edit source]
References[edit | edit source]
- Feingold (1992)
- Fuller, R. C., Houle, D., & Travis, J. 2005. Sensory Bias as an Explanation for the Evolution of Mate Preferences. [Abstract]
- Bressler ER, Martin RA, Balshine S. 2006. Production and appreciation of humor as sexually selected traits. Evolution and Human Behavior, 27(2), 121-130. [Abstract]
- Matsuura K. 2014. A new pufferfish of the genus Torquigener that builds "mystery circles" on sandy bottoms in the Ryukyu Islands, Japan (Actinopterygii: Tetraodontiformes: Tetraodontidae). Ichthyological Research. Vol 62.2, pp. 207–212. [Abstract]
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4415372/ (Mitchem 2016)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4757567/ (Talamas 2016)
- http://doi.org/10.1177/1474704918800063 (Lassek 2018)
- https://doi.org/10.1016/j.evolhumbehav.2014.06.004 (Nedelec 2014)
- http://doi.org/10.1016/j.evolhumbehav.2018.06.003 (Arnocky 2018)
- http://doi.org/10.1016/j.paid.2013.08.029 (O’Connor 2014)