Transcription
If an alien zoologist were to study humans alongside all the other animals on Earth, they'd probably find us to be pretty strange. When one of the few creatures to care highly about a female partner's attractiveness, this is quite paradoxical because sexual selection impacts males more intensely than females. With peacocks, for example, the male has the brightly colored plumage, and the females are quite bland. It's a male peacock's job to attract the partner, and they don't really care what she looks like. Male proboscis monkeys attract partners by the size of their nose, and again, they don't care who the partner is. In humans, however, physical attraction is a key component for both genders.
Sexual selection and facial neoteny, by Doug Jones, hypothesizes that we care about female attractiveness, or more specifically, indicators of youthfulness, because we live longer and display more exaggerated age-related cues. If you're going to choose someone for 50 years, you'd want to choose someone that indicates that they're going to age well. This is where the concept of neoteny comes into play. Facial neoteny, or juvenilization, is the idea of retaining baby-face features throughout maturation.
To understand why we choose certain features, you need to backtrack a few steps, and we'll take a look at evolutionary biology. We tend to think of humans as being freed from the biological impulses that plague lesser animals; that our sexual selections are a product of centuries of refined culture, and animals are a simple product of biology, and that there's no such thing as natural human beauty. [Music] Animals, like humans, can imprint certain mate preferences influenced early on during development, like when Taylor Lautner imprints on Bella and Edward's baby girl. Even at 14, there was a pretty weird scene. This is an example of animals experiencing culture.
On the other hand, in the famous experiment by Longhua in 1987, human infants prefer more conventionally attractive faces and spend more time looking at those. The test was repeated with attractive faces from five different races, producing the same results. This is an example of human biological preference. Now, a lot of the scientific literature on the topic comes from Western society or Western-influenced ones. To prove that youthfulness is a universal feature, indigenous populations of South America were contacted, the Arara and the Yanomama people, in the 1970s. After showing them a set of photos, the Arara people, as hypothesized, posed the most near-to-average faces, in particular East Asian ones, which they had never seen before. These responses are in line with studies conducted on the Japanese upon their first contact with the West. Although all had a correlation, the correlation between neoteny and attractiveness was much stronger in the West than in the indigenous population, suggesting both a universal and culture-specific element to neoteny.
The reality is our obsession with youthfulness is partly hardwired criteria, and the remainder is filled in with learned culture. As learning requires cost, we've evolved to have the basics of genetic attractiveness pre-programmed from birth to save some time. Now, there's two theories surrounding why we like neotenous faces and youthfulness. One is that it's invariably linked with fecundity and fertility. As males stay fertile well up into their 60s, having youthful indicators are not a largely beneficial trait to them. However, as females lose fecundity much earlier, these features are all the more valuable on them. In a study by Barry and MacArthur (1986), men rated the intermedia juvenalized face as the most attractive. So there's a nuance to neoteny that needs to be further explored; it's not just the most young-looking face that we find the most attractive.
The second theory, presented by Gao et al. (1992), and I paraphrase, is that men prefer juvenalized women so that they feel more dominant around them and that they're easier to control. However, Kenrick in 1994 found that teenage participants preferred more mature faces and more mature women than them, putting into question that selection is all about patriarchal power and control. Instead, it posits a counter-argument that males prefer peak fecundity, and so that 20-to-30 range, albeit being older than the teenage participants of the preferred selection.
Another interesting point about neoteny is that individuals can be more or less attractive than others of the same age, in part because they have facial proportions associated with younger or older ages. The best example is Angelina Jolie, who's considerably older than other Hollywood stars but is still considered a beauty icon because of her neotenous features. Her slightly larger, rounded forehead, full cheeks, and flat nose bridge contrast with her adult features of having a very strong jaw and maxilla. She is the perfect example of an intermediate juvenalized face that has the best of both worlds. Another example that I covered last week was Audrey Hepburn; her at age 60 still looks better than most people because she has very similar features, in particular the forehead shape, albeit her jaw is a bit less prominent.
The reason we associate cuteness with youth is because of how baby's craniofacial features develop when they're young. The skull and its housing are top-heavy because the main features of aging—the jaw, the masseter muscles, and the nose—haven't developed yet. Through development, faces become more bottom-heavy, and this process is modeled by a mathematical transformation called a carrier doll strain. So female attractiveness and neoteny is not really determined by one individual feature per se, but their relationship in harmony to others and how they fit this ideal carrier doll map. Upper and middle third features—ammonia tonus—when stretched out and exaggerated laterally and hence rounded foreheads, large eyes, and flat nose bridges pair so well with contrasting, least strong jaws. In one study, adjusting the carrier doll strain positively resulted in low attractiveness ratings for both men and women. Adjusting the strain negatively—so more top-heavy and neotenous—resulted in higher ratings for women and lower ones for men. Conventionally unattractive female test subjects benefited heavily from a more neotenous morph, while the attractive and intermediate groups didn't as much. Inversely for men, the most attractive men were impacted the most heavily from neotenous features, while the intermediate and low groups benefited more from this. We can gather that having a neotenous face is a more logarithmic diminishing return benefit to attractiveness, much like high in both men and women; it's important up until a certain point where it's just not as beneficial anymore. However, neoteny acts inversely in men and women, being a benefit to one and a cost to another.
In another study by doctorate students and models, had their symmetry measured, with the models, as expected, having more neotenous faces, with everything being a slight few standard deviations larger in the upper and middle third. I found this pretty funny, but the predicted age for the models was an average of seven years, and the students got twenty. As Doug stated, this does not mean that facial proportions of models match those of real seven-year-olds, since the ages predicted by these equations are based on naive linear extrapolation of age-related changes in adult facial proportions. Human faces obviously don't age linearly; it's much faster during puberty and continues on slowly forever. If adjusted for non-linear extrapolation, our guess at the models look around eighteen, and the average students look around thirty. Because the difference between the extrapolated twenty and seven is still quite large, I guess this helps explain Leo's dating choices.
There is a very real and social benefit to neoteny. Baby-face features get more help from others. In this study, participants were given equal resumes; the only variants being their resume photos were more or less neotenous or mature. They then went around losing these resumes randomly around metropolitan areas in Nairobi, Kenya, and the US and measuring how many were actually returned. Three out of the four groups that did benefit from having more neotenous features, which is represented by the line in gray. From the same study, neotenous faces were also seen as more submissive and weak across both genders. Take from that what you will, but you can play it to your advantage and have the best of both worlds. Take David Laid on YouTube; no one is going to call him submissive to his face.
Quick announcement: We have a Twitter now, and we post a lot of the things that we can't fit into a video during our research, but we still think you can benefit from. Like, did you know that baby-face defendants get a lower conviction rate for the same crime?