Tuesday, July 10, 2018

It's not self-hate

Long-haired Sango woman, Democratic Republic of the Congo (Friedrich 1913, Fig. 174)

A competitive mate market will reward individuals whose secondary sexual characteristics seem abnormally bigger or flashier. A "supernormal stimulus" has a stronger visual impact than a normal one, and the behavioral response is correspondingly stronger. This effect has been studied in many animal species. When, for instance, a female butterfly passes by a male, the latter is attracted to the flashing wing pattern. The same pattern on a rotating drum exercises the same power of attraction, which increases as the speed of rotation increases—up to almost ten times the speed of a normal wing-beat (Manning 1972, pp. 47-49).  

A human example? Head hair. It has become much longer than hair elsewhere on the body, apparently because it holds some power of attraction. This lengthening has been brought about by several evolutionary changes: faster rate of growth, longer growing phase, higher density, and greater resistance to physical damage (Khumalo 2005; Loussouarn 2001; Loussouarn et al. 2005). These changes have gone farther in some populations than in others. Darwin noted "the extraordinary difference in the length of the hair in the different races; in the negro the hair forms a mere curly mat; with us it is of great length, and with the American natives it not rarely reaches to the ground" (Darwin 1936[1888], p. 906).

Long hair is the "derived" form. It evolved in those modern humans who left Africa for northern Eurasia, including some who later back-migrated to the tropics, such as the Austronesians of Southeast Asia and Oceania and the Amerindians of the tropical New World.

Short, frizzy hair is the ancestral form. Today, it is seen in sub-Saharan Africans and in some remnant groups that remained in the tropical regions of South Asia, Southeast Asia, and parts of Oceania. These groups are the Andamanese of India, the Semang of Malaysia, the Aeta of the Philippines, and the natives of Australia, Papua New Guinea, and Melanesia.

Long head hair, a component of the Kindchenschema

The ancestral hair form is straight and silky in a newborn child: "[...] the majority of African babies are not born with springy tight curls, the African child at birth is either bald or has silky loose curls similar to the Jheri curls" (Ajose 2012). This physical difference was cited by Zambian students when asked to describe how Africans look. Some of the girls "noted that African babies were born with white skin and long hair" (Powdermaker 1956).

Although adults normally have loose, silky hair in most of the world, this was not so in ancestral humans. Such hair was specific to infants and thus formed part of what Konrad Lorenz dubbed the Kindchenschema—a set of visual, auditory, and tactile cues that identifies a human infant to adults, who then feel less aggressive and more willing to provide care and nurturance (Lorenz 1971, pp. 154-164). The infant seems "cute."

This has been no less true in sub-Saharan Africa, and a desire to be similarly cute has led African women to make their own hair longer, looser, and silkier. Some of their techniques predate the colonial era:

Africa as the cradle of mankind is likely to have had hair care since the beginning of human existence. Partly because of the oral tradition of passing down history, it is difficult to corroborate evidence of hair care. But probably the earliest form of hair straightening was the molding of hair into shapes using various clays and mud (e.g., indicating the station of a married woman among the Zulu's). [...] Hair was also lengthened with fibers and grasses, much as is done for braids with synthetic extensions nowadays. Although small decorative comb-like structures have been discovered with archeological finds, it is not clear whether original Africans combed their hair or if these implements were purely decorative. Although not written down, fascinating stories of more recent hair care (and hair disasters) are often told by older women about straightening hair using hot stones even before hot combs became available. (Khumalo 2008: see also Sieber and Herreman 2000)

In 1721, John Atkins provided an early description of women braiding and dressing their hair in Sierra Leone:

[The women] work hard at Tillage, make Palm-Oil or spin Cotton, and when they are free from such work, the idle Husbands put them upon braiding, and fettishing out their woolly hair, (in which Sort of Ornament they are prodigious proud and curious) keeping them every Day, for many Hours together at it. (Sieber and Herreman 2000, p. 67)

West African women still lavish much time on their hair:

"Big hair," "plenty of hair," "much hair"—West African communities, including Mende, admire a fine head of long, thick hair on a woman. Both these elements are crucial: thickness and length. Thickness equals increase in the number of individual strands, and the length is proof of strength. Growing such luxuriant hair requires a Mende woman's patience and care. Because a man's hair is kept shaved or cut close to the scalp, people say that "men don't have hair." Beautiful hair thus is a distinctly female trait; the more of it, the more feminine the woman. (Boone 1986, p. 184)

This hairdressing tradition is ancient enough to have spawned myths, such as this one among the Mende:

It is known among Mende that all the "water people," angels, have marvelous hair. The mermaid Tingoi is known by her long, wavy hair and her glamorous habit of dressing it with a golden comb while seated on a rock. A little girl with especially long hair is feared to be in danger of drowning because she will be very attractive to the "water people," who may think she is one of them and wish her to join them. (Boone 1986, p. 192)

Long-haired women appear in the folklore of other African peoples. Among the Yoruba, a folk-tale explains "why women have long hair." A woman fell into a pit and was pulled out by her hair, which thereby became as long as a man's arm. She initially felt ashamed of her new appearance and hid herself.

But after a while she realized that her long hair was beautiful, and then she felt very proud and scorned all the short-haired women, jeering at them. When they saw this, they were consumed with jealousy, and began to be ashamed of their short hair. "We have men's hair," they said to one another. "How beautiful it would be to have long hair!"

So one by one they jumped into the pit, and their friends pulled them out by the hair.

And in this way they, and all women after them, had long hair. (Ogumefu 1929, chap V)

Another Yoruba folk-tale recounts how a king had a beautiful daughter with hair "so long that it touched the ground when she walked." But she lost her hair and regained it only after a man found a tree that bore human hair. She then became his wife. (Abrahams 1983, pp. 59-63)

Lengthening of women’s hair seems to have been most common in West Africa, but it was also practiced in central and southern Africa during early colonial times. Women of the Manyema (Tanzania) were described as having “an abundance of hair” that would “flow down to the waist in masses of ringlets” (Bettany 1892, p. 661). Among the Sango (DRC), girls old enough for marriage would plait long strands of string into their hair to create long manes (Friedrich 1913, pp. 190-191). Young women of the Mbalantu (Namibia) achieved the same effect by braiding sinew extensions (Sieber and Herreman 2000, p. 65). Nonetheless, such practices seem to have been uncommon in southern Africa. When a black South African woman traveled to the United States in the 1930s, she was struck by the number of African American women who straightened and extended their hair. “What really made me feel strange [was] nearly every girl and woman has long hair and I among them looked like a boy dressed in girl’s clothes” (Thomas 2006, p. 487).

It appears that African American women were already braiding and threading their hair at an early date. Men, however, often shaved their heads—an indication that both sexes viewed long head hair as a female ornament (White and White 1995).

In sum, hair lengthening is an African tradition that precedes colonial contact with Europeans. From the beginning, the aim was to look feminine, and not "white." The motive was not self-hatred but sexual fantasy—a desire for the supernormal, a wish to become a woman with a long mane of hair. This may be an example of humans creating in one part of the world through artificial means what has been created elsewhere through biological evolution. The same desire has been satisfied in different ways.

Evolution of long head hair in Homo sapiens

African hair can revert to the loose, silky form of infancy as a result of some illnesses: AIDS, rheumatoid arthritis, systemic lupus erythematosus, pulmonary tuberculosis with cachexia, and Behçet's disease (Ajose 2012). These illnesses somehow disrupt normal hair growth, and it is plausible that a similar disruption of genetic origin, i.e., a loss-of-function allele, was the first stage in the evolution of long head hair.

Head hair began to lengthen as ancestral humans spread out of Africa and into the temperate and arctic zones. These environments shifted the pressure of sexual selection from men to women. On the one hand, male mortality increased in relation to female mortality because men had to hunt over larger expanses of land. On the other hand, the polygyny rate decreased because it became costlier to provide for a mother and her offspring, particularly during winter. Men were scarcer on the mate market, being fewer in number and less polygynous. (Frost 2006; Frost 2014; Frost 2015).

Women were now in excess supply, and the spotlight of sexual selection was on them. Their physical characteristics became flashier, bigger, or somehow exaggerated. In the case of head hair, the existing practices of artificial lengthening helped show the way for future evolution. The cultural became biological. Over succeeding generations, the infant hair form persisted more and more into adulthood while becoming ever longer and straighter, eventually reaching down to the waist if left uncut. Hair seems to have lengthened within the whole of northern Eurasia, rather than within the smaller zone of steppe-tundra where skin became white and where hair and eyes became brightly and diversely colored. Hair lengthening was thus triggered by a lower intensity of sexual selection.

This selection pressure acted primarily on women and then secondarily spilled over onto men, perhaps because most of the genes in question are weakly sex-linked, as are most genes. Nonetheless, there is some sex linkage. Scalp hairs have a greater mean diameter and hence more volume in women, even in the shorter-haired New Guineans (Walsh and Chapman 1966). Hair growth rate and final length are also somewhat greater in women than in men (Sigler 2011, p. 13). Men furthermore tend to lose their head hair, often as early as their twenties. In general, growth of head hair is under stronger hormonal inhibition in men than in women (Kondo et al. 1990).


Before ancestral humans began to spread out of Africa, women were already pushing the phenotypic envelope by artificially making their hair straighter, longer, and silkier. Later, outside Africa, evolution brought this fantasy to life. As Charles Darwin concluded, such hair serves an ornamental purpose in our species: "for we know that long tresses are now and were formerly much admired, as may be observed in the works of almost every poet; St. Paul says, "if a woman have long hair, it is a glory to her." (Darwin 1936[1888], p. 906).


Abrahams, R.D. (1983). African Folktales. Traditional Stories of the Black World. New York: Pantheon Books.

Ajose, F.O.A. (2012). Diseases that turn African hair silky. International Journal of Dermatology 51 (supp. S1): 12-16.

Bettany, G.T. (1892). The World’s Inhabitants or Mankind, Animals, and Plants. London: Ward, Lock, Bowden and Co. 

Boone, S.A. (1986). Radiance from the Waters: Ideals of Feminine Beauty in Mende Art. New Haven and London.

Darwin, C. (1936 [1888]). The Descent of Man and Selection in relation to Sex. reprint of 2nd ed., The Modern Library, New York: Random House.

Friedrich, A. (1913). From the Congo to the Niger and the Nile. An account of the German Central African Expedition of 1910-1911 by Adolf Friedrich Duke of Mecklenburg, vol. 1. London: Duckworth and Co.

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior 27(2): 85-103.

Frost, P. (2014). The puzzle of European hair, eye, and skin color. Advances in Anthropology 4(2): 78-88. 

Frost, P. (2015). Evolution of long head hair in humans. Advances in Anthropology 5(4): 78-88.

Khumalo, N.P. (2005). African hair morphology: macrostructure to ultrastructure. International Journal of Dermatology 44(Suppl. 1): 10-12.

Khumalo, N.P. (2008). On the history of African hair care: more treasures await discovery. Letter to the Editor. Journal of Cosmetic Dermatology 7(3): 231.

Kondo, S., Y. Hozumi, and K. Aso. (1990). Organ culture of human scalp hair follicles: effect of testosterone and oestrogen on hair growth. Archives of Dermatological Research 282(7): 442-445.

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

Loussouarn, G. (2001). African hair growth parameters. British Journal of Dermatology 145(2): 294-297.

Loussouarn, G., C.E. Rawadi, and Genain, G. (2005). Diversity of hair growth profiles. International Journal of Dermatology 44(Suppl. 1): 6-9.

Manning, A. (1972). An Introduction to Animal Behaviour. 2nd edition. London: Edward Arnold.

Ogumefu, M.I. (1929). Yoruba Legends. London: The Sheldon Press. 

Powdermaker, H. (1956). Social change through imagery and values of teen-age Africans in Northern Rhodesia. American Anthropologist 58(5): 783-813.

Sieber, R. and F. Herreman. (2000). Hair in African Art and Culture. African Arts 33(3): 54-96.

Thomas, L.M. (2006). The modern girl and racial respectability in 1930s South Africa. Journal of African History 47(3): 461-490

Walsh, R.J., and R.E. Chapman. (1966). A study of the quantitative measurement of human head hair fibres. Man, new series. 1(2): 226-232.

White, S. and G. White. (1995). Slave Hair and African American Culture in the Eighteenth and Nineteenth Centuries. The Journal of Southern History 61(1): 45-76.


Anonymous said...

Peter, what is your view on male pattern baldness? Do you suppose there is some evolutionary reason for it?

Sean said...

Because MPB is commonest in Europeans, I suppose it is a side effect of selection for women having abundant hair or looking good in other ways.

Anonymous said...

Isn't MPB tied to testosterone?

This article claims MPB is most common among Europeans, although the map in the article suggests that MPB is more common among Mediterranean populations, that is Southern Europeans, Middle Easterners, and North Africans, than among Northern Europeans:


MPB prevalence appears to correlate with male androgenic hair i.e. male body hair prevalence, which is produced by testosterone:


Drugs like steroids cause male hair loss as a side effect, and drugs used to treat MPB like finasteride disrupt testosterone.

ItsTheWooo said...

I would assume if hair is sexually dimorphic, and it absolutely is, MPB is a side effect of a normal androgen mediated process to make the hair thinner , so creating a more masculine and intimidating appearance.

THat some men become bald is a side effect of androgens inhibiting hair growth/reducing follicles to promote an older more masculine appearance that might be an advantage in conflicts or general social success.

Sort of how the reverse is true in women, pregnancy with high levels of female hormones the hair becomes very thick (exaggerated hormone state) and then there is shedding of hair after childbirth because of withdrawal.

Wanda said...

ISTM that MPB would be selected against because, anecdotally at least, women prefer men with a good head of hair -- that's why men do comb-overs, wear wigs, and have traditionally thrown away money on quack baldness cures.
The shaved-head as a super macho look seems to be a fairly recent fad. Thus so many derogatory names for chrome domes, skullets, cue balls, slapheads, turtle waxers, etc.

Peter Frost said...

I once toyed with the idea that MPB evolved as a means to deter older men from abandoning their wives and re-entering the mate market. If that were the case, however, it would be less common in societies where older men are normally polygynous.

Well, back to the drawing board.

Jcrezyyy977 said...

You know despite the epidemic of sistahs wearing weaves, black women can actually grow long hair NATURALLY-if it's braided or corn-rowed :).

Anonymous said...

Can I ask if you disagree with what's now the concensus molecular tree? Because what you're saying makes more sense if Melanesians and Negritos diverged from the Eurasian mainline before Euros and Asians split.

Anonymous said...


They belong to brittle-hair species.

J said...

I wonder from where we got that Harpo Marx style hair among Ashkenazim.

BTW, St.Paul was no poet.

Anonymous said...

@J, woolly hair gene expression is sporadic in other animals, mostly under domestication. For example in Bridlington terriers and wool producing sheep. The appearance of such hair sporadically in lab rodents was of interest to geneticists at the time. Only its distribution within man has puzzled anthropology re: hypotheses connecting Melanesian and 'Negrito' populations to Africa more closely than nearby (supposedly Caucasoid!!) Australians, as though the one trait of hair texture out-weighed the similarities shared by Melanesian and Australian crania. Since only one or two genes were involved its no big deal.

I think a better question is why 'unsexy' frizzy hair came under enough positive selection in some humans that it won out against the selection toward 'sexy' long hair.

Anonymous said...

@Wanda, people often find the skinhead look intimidating, so genetic pacification would select against it whatever its origin is.

Anonymous said...

@ Anonymous July 15, 2018 at 6:10:00 AM EDT

Have you ever wonder if the same genes are responsible for curly hair in Blacks and woolley monkyes(Lagothrix lagotricha)?

Anonymous said...

@Anonymous, I'm not sure which gene is responsible in the monkeys but Joseph Deniker explicitly compared their hair texture to Africans as a matter of fact. However I met and cared for woolly monkeys lately and though the hair is unusual it isn't exactly frizzled when you look close. (They're very nice natured so its easy to look at them close while they hug and groom you.) Atelines canonically lack underfur however the ADW says "The hair is dense, short, thick, and predominantly composed of underfur" - which is probably a mistake based on the curiousness of the texture.

Wanda said...

I dunno. I've never found baldies intimidating. To me, actor Wallace Shawn typifies the chrome dome --a hapless worker bee: Homer Simpson is bald; Conan the Barbarian, He-Man and Tarzan are not. (^_^)

Anonymous said...

@Wanda, it might be a UK thing because of skinhead culture in the past. The look was only popularised in the UK because of a popular TV show called EastEnders and the Grants were seen as ideal hard men who the public wished to emulate.

MPB is a mystery because its existence overrides sexual selection, much as short and frizzy hair has done in some places outside of Africa. Although sexual selection has created some impressive structures in nature it seems to me its benefits can be easily overridden. But that still leaves the question of to what benefit. I always suspect disease resistance as the default explanation but who knows?

Sean said...

Wanda, Curly of the three Stooges and Vince McKay of the cop show the Shield were portrayed by the same naturally balding and chubby actor, but he lost weight gained muscle and became an intimidating shaved-bald to play MacKay. Shaving one's head is like lifting weights and wearing shades. look at Jeff Bezos before and after, he is making the best of a bad job.

Anony, Well being bald could stop one catching a sexually transmitted disease, but why only for men? Sexual selection can work on women or on men. Not both. If hair is under sexual selection, and only men get bald, something that is not an advantage in attracting women, then MPB is most likely a side effect of sexual selection of women's hair.

Anonymous said...

@Sean, its just disease resistance (and not neccessarily STIs) explains a lot of pleiotropic effects. It is undooubted that long hair is attractive in women, but it is also attractive in men as Wanda noted fe. long haired rock stars. Furthermore many cultures have religious taboo bout cutting mens hair because hair is thought to be virile - Samson being the best known example. This is the same ind of taboo surrounds facial hair fe. Norse and Kurdish taboos against cutting facial hair. My thoughts are more why the situation had reversed perhaps a few times in the Old World tropics and at the very least once.

Sean said...

You are mixing up long hair and thick hair. A thick head of hair makes you look assertive and is attractive to women, going by actors and models, but in real life if you are noticeably bald you get your remaining hair cut very short or maybe shave it all off if looking assertive is important to you. If long hair was super attractive, and baldness was a marker for superior disease resistance, then accentuating your bald areas by leaving a noticeable fringe of long hair around a bald pate would be a highly popular strategy. It isn't, for reasons which ought to be obvious. Gregory Cochran and Razib Khan used to pretend they thought white skin was to do with disease resistance, it's ye olde HBD all purpose hand waving explanation.

Anonymous said...

@Sean, lots of male sex symbols and role models, as Wanda and I have pointed out, are long haired and proud of it. There is undoubtedly sex selection for long hair in women: perhaps hair length in men isn't under positive selection at all?

I'm unsure about skin colour because it doesn't match the obvious solutions as much as you'd think. I'm 100% certain the LCA of H. saps was not black because 1) the Sandawe aren't black and 2) Australian Aboriginal skin doesn't have quite the same pigmentation as African skin.

Sean said...

I never contrasted long hair and shaved hair without reference to the crucial factor of MPB. I think it is a matter of common obsevation that few men with MPB grow what is left of their hair long, and conversely few men with no trace of MPB shave their head. A man's hair looks good to everyone if it is thick and dense, it may look even better to women if, in addition to being thick and dense, it is grown long, but MPB kills your chance of having great hair and you look stupid with MPB and the remaining hair grown long--that just emphasizes the bald patch. If someone has MPB and wants to make it less obvious, he cuts his hair very short or even shaves it all off. A shaved head is uniform in appearance, with no bald patches, and so a shaved head is actually as close to the impact of thick dense hair as one can come once afflicted with MPB. So those, especially younger men, with MPB, who are particularly concerned with looking like they are physically capable, (eg balding bouncers), often shave their heads. Baldness is a marker for declining health: Early baldness higher heart disease risk factor than obesity, says study.

Anonymous said...

@ Anonymous, July 17, 2018 at 6:15:00

'variants associated with dark pigmentation in Africans were identical by descent in southern Asian and Australo-Melanesian populations.'

Anonymous said...

@Anonymous, that public release fails to link to a paper. The wording is a bit ambiguous and I suspect whoever wrote it didn't properly understand the implications: f.e. 'one of the light pigmentation variants near the SCL24A5 gene locus was introduced into East Africa by gene flow from non-Africans'... does this refer to Sandawe and are they saying South African Bushmen were once black? Before the non-African variant reached SS Africa from outside?