Survival of the cutest

Blond hair in Oceania

Blond Vanuatu boy (source: Graham Crumb, Wikicommons)

Blond hair evolved independently in Oceania. As in Europe, it’s more common in children and women, but the age and sex differences are larger. Since it coincides geographically with risk of infant death due to maternal neglect, it may have been favored by mothers ensuring the survival of “cute” infants.

If we exclude people of European descent, we find that blond hair is most common in Oceania, specifically among people native to a zone stretching from central and western Australia, through Papua New Guinea, and into Melanesia and nearby islands. Unlike the case with Europeans, this blond hair coexists with dark skin and dark eyes. It is due to a TYRP1 allele that occurs almost nowhere else (Kenny et al., 2012).

Oceanic blondism varies by age and sex. The Aborigines of central Australia are about 85% fair-haired and 15% dark-haired up to ten years of age in both sexes. Male hair then darkens to a color from medium brown to black and is almost always dark by the age of twenty. In contrast, female hair darkens only after twenty and is seldom darker than light brown even in old age (Abbie & Adey, 1953). Similar age and sex differences are seen among Solomon Islanders (Norton et al., 2006). Thus, blond hair is common in both sexes during childhood before becoming largely confined to women.

European hair likewise darkens after childhood, and again much more in boys (Olivier, 1960, p. 74; Steggerda, 1941). According to a genomic study of 300,000 participants of European descent, women are more likely to have blond or red hair and three to five times less likely to have black hair:

Our work identified over a hundred new genetic loci involved in hair pigmentation in Europeans and raises interesting questions. First, the observation of higher prevalence of lighter hair colors among women … follows previous findings based on objective quantitative measurement of hair color, suggesting that sex is truly associated with hair color, independent of socially driven self-reporting bias. (Hysi et al., 2018; see also Frost et al., 2017, Shekar et al., 2008).

Although some selection for blond hair may exist everywhere, it seems to have been strong enough to produce a visible effect only in Europe and parts of Oceania.

Evolution of Oceanic blondism

Why did blond hair evolve in Oceania? One reason may be an aesthetic preference:

In Samoa, all fair hair is considered 'ena'ena, a word that is usually translated as brown, although when English-speaking Samoans use this term in reference to hair, they typically gloss it as 'blond'. This makes sense since, when one is bleaching Polynesian hair, it goes through a series of reddish- brown shades prior to arriving at blond, and even then retains a reddish hue. When describing hair, Samoans specify the actual shade of 'blond' by using certain modifiers with 'ena'ena, such as 'ena'ena manaia, which literally means 'really nice brown hair', but which refers to a very fair reddish colour.

The hair of female spirits is most commonly said to be 'ena'ena manaia, and they are wont to decorate it with a red hibiscus. (Mageo, 1994)

This aesthetic preference may protect blond-haired infants from maternal neglect. Papua New Guinea has a relatively high rate of child malnutrition—35% on average and up to 78% in some regions, including regions where adults are well fed. The cause seems to be neither environmental nor ecological but rather cultural (Lepowsky, 1987, p. 75). In some cultures of Papua New Guinea, mothers deliberately withhold infant care:

These women take a guarded attitude toward infants, extending the greatest amount of their affection and parental care toward children who are physically strong and who survive the first couple of years of life. (Lepowsky, 1987, p. 78)

Because a newborn child has uncertain chances of survival, it remains unnamed for a few weeks after birth, and the father's kin is ritually thanked only after a six-month wait. Until then, the chances of survival will depend on the mother’s feelings toward her child.

The evolutionary consequences are discussed in a paper by child psychologist Judith Rich Harris, who attributed human hairlessness and pale skin to parental fascination with certain tactile and visual stimuli: “The use of infanticide as a method of birth control in premodern societies gave parents – in particular, mothers – the power to exert an influence on the course of human evolution by deciding whether to keep or abandon a newborn infant.” The infant would more likely be kept if it seemed cute in one way or another (Harris, 2006).

Selection for cuteness?

The ethologist Konrad Lorenz believed that we are hardwired to perceive certain infant features as “cute”—large eyes and forehead in relation to the lower face; small nose and chin; and soft, smooth, pale skin. This is what he called the Kindchenschema (Doebel et al., 2022; Golle et al., 2013; Kis, 2021; Lorenz, 1971, pp. 154-164). Perceived cuteness reduces child neglect, which harms not only the child but also the parents, since they are seeking to perpetuate themselves through procreation.

Neglect, if especially frequent, will favor not only existing “cute” traits but also new ones, such as hair colors that catch attention through their brightness and “purity” (i.e., they occupy thinner slices of the visible spectrum). Because such colors are fascinating, they induce the observer to take a closer look.

Lorenz argued that pure colors inherently appeal to our sense of beauty:

I do not think it too far-fetched an explanation to suppose that the striking orderliness and regularity which so strongly appeals to our sense of beauty in the coloring, the notes and the display movements of so many animals, especially of birds, has its source in their nature as releasers [i.e., stimuli that “release” strong interest] and in the general tendency of all releasers to develop in the direction of the more improbable. This would also explain the astonishing rhythm that we meet in very nearly every releasing action. The more or less pure spectral colors which so often appear in color patterns functioning as releasers, very probably also find their explanation in this way, since the reflexion of one wavelength among the wave-mixture of white light is in itself rather improbable, so improbable indeed that color alone may, in some cases, function as a releaser. (Lorenz, 1937, p. 249)

There remains the question as to why selection for blond hair has acted not only on children but also on women, both in Oceania and in Europe. Women resemble infants in certain visible, tactile, and audible ways—a “baby” face, a light complexion, a smooth skin texture, and a high vocal pitch (Frost, 2023). The ethologist Wolfgang Wickler suggested that this apparent mimicry likewise arose from a need to reduce neglect and abuse:

… on a purely external basis, woman looks much more “paedomorphic,” i.e., more childlike, than man. On an average, in every race, she is 7 percent smaller than he, has relatively shorter limbs and a rounder face, and her nose and chin are less marked. Whatever the reason for this, one result is that it prevents the man from behaving like a rabid aggressor, and makes it easier to him to fulfill his role of guardian and protector (Wickler, 1973, p. 264)

This is sexual selection only in a broad sense, since it extends beyond the moment of mate choice to encompass the long period of cohabitation after mating. Nonetheless, one thing is shared by these “narrow” and “broad” forms of sexual selection, and also by the selection that a mother exercises over her newborn child. In all three cases, the “selector” is a loved one—a spouse or a parent—who is selecting those individuals who have an endearing physical appearance.

References

Abbie, A.A., & Adey, W.R. (1953). Pigmentation in a central Australian tribe with special reference to fair-headedness. American Journal of Physical Anthropology, 11(3), 339-359. https://doi.org/10.1002/ajpa.1330110310

Doebel, S., Stucke, N. J., & Pang, S. (2022). Kindchenschema and cuteness elicit interest in caring for and playing with young children, but less so when children are masked. Scientific Reports, 12(1), 11903. https://doi.org/10.1038/s41598-022-15922-z

Frost, P. (2023). The original meaning of skin color. Aporia Magazine, February 7.

Frost, P., Kleisner, K., & Flegr, J. (2017). Health status by gender, hair color, and eye color: Red-haired women are the most divergent. PLoS One 12(12): e0190238. https://doi.org/10.1371/journal.pone.0190238

Golle, J., Lisibach, S., Mast, F. W., & Lobmaier, J. S. (2013). Sweet puppies and cute babies: Perceptual adaptation to babyfacedness transfers across species. PloS one, 8(3), e58248. https://doi.org/10.1371/journal.pone.0058248

Harris, J.R. (2006). Parental selection: a third selection process in the evolution of human hairlessness and skin color. Medical Hypotheses, 66(6), 1053-1059. https://doi.org/10.1016/j.mehy.2006.01.027

Hysi, P.G., Valdes, A.M., Liu, F., Furlotte, N.A., Evans, D.M., Bataille, V., et al. (2018). Genome-wide association meta-analysis of individuals of European ancestry identifies new loci explaining a substantial fraction of hair color variation and heritability. Nature Genetics, 50(5), 652-656. https://doi.org/10.1038/s41588-018-0100-5

Kenny, E.E., Timpson, N.J., Sikora, M., Yee, M-C., Moreno-Estrada, A., Eng, C., Huntsman, S., Burchard, E.G., Stoneking, M., Bustamante, C.D., & Myles, S. (2012). Melanesian blond hair is caused by an amino acid change in TYRP1. Science, 336(6081), 554. http://dx.doi.org/10.1126/science.1217849

Kis, I. (2021). Kindchenschema: The science of cute. Imperial Bioscience Review, February 12. https://imperialbiosciencereview.wordpress.com/2021/02/12/kindchenschema/

Lepowsky, M. (1987). Food taboos and child survival: A case study from the Coral Sea, in N. Scheper-Hughes (Ed.) Child Survival: Anthropological Perspectives on the Treatment and Maltreatment of Children (pp. 71-92), Springer. https://doi.org/10.1007/978-94-009-3393-4_4

Lorenz, K. (1937). The companion in the bird's world. The Auk, 54(3), 245-273. https://doi.org/10.2307/4078077

Lorenz, K. (1971). Studies in Animal and Human Behaviour, vol. 2. London: Methuen & Co.

Mageo, J.M. (1994). Hairdos and Don'ts: Hair Symbolism and Sexual History in Samoa. Man, New Series, 29(2), 407-432. https://doi.org/10.2307/2804480

Norton, H.L., Friedlaender, J.S., Merriwether, D.A., Koki, G., Mgone, C.S., & Shriver, M.D. (2006). Skin and Hair Pigmentation Variation in Island Melanesia. American Journal of Physical Anthropology, 130(2), 254-268. https://doi.org/10.1002/ajpa.20343

Olivier, G. (1960). Pratique anthropologique. Paris: Vigot Frères.

Shekar, S.N., Duffy, D.L., Frudakis, T., Montgomery, G.W., James, M.R., Sturm, R.A., & Martin, N.G. (2008). Spectrophotometric methods for quantifying pigmentation in human hair-Influence of MC1R genotype and environment. Photochemistry and Photobiology, 84(3), 719-726. https://doi.org/10.1111/j.1751-1097.2007.00237.x

Steggerda, M. (1941). Change in hair color with age. Journal of Heredity, 32(11), 402-403. https://doi.org/10.1093/oxfordjournals.jhered.a104977

Wickler, W. (1973). The Sexual Code. The Social Behavior of Animals and Men. Garden City: Anchor Books. https://archive.org/details/sexualcodesocial0000wick_k7k0