Naked Love: The Evolution of Human Hairlessness

Abstract

All primates except human beings have thick coats of body hair. This suggests the primate ancestors of human beings likewise had such body hair and that, for some evolutionary reason, lost their body hair. Various theories have been put forward but none is fully adequate. This article presents the “naked love theory.” This theory locates the origin of human hairlessness in the ancestral mother-infant relationship. In this view, hairlessness is ultimately the adaptive consequence of bipedalism. Because of bipedalism, ancestral infants lost their prehensile feet and thus lost the ability to grasp the mother’s fur with their feet, as do other primate infants. Early bipedal mothers were thus under pressure to carry the infant. Therefore infants survived only if mothers had a strong desire to hold them. Because of the pleasure of skin-to-skin contact, the desire to hold the infant would have been stronger in mothers possessing a hairless mutation that enabled them to give birth to hairless infants. Survival of these infants would have then been greater than that of hair-covered infants. The hairlessness that began to appear in this context of maternal selection was then reinforced by sexual selection in the male-female sexual relationship. This is because a hairless sexual partner would have enabled the hairless individual to recreate the pleasure of skin-to-skin contact in the mother-infant relationship. This theory then helps to explain the evolutionary origins of romantic love.

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References

  1. Amiel-Tison C, Grenier A (1986) A Neurological Assessment During the First Year of Life. New York: Oxford University Press.

    Google Scholar 

  2. Avery MD, Duckett L, Frantzich CR (2000) The experience of sexuality during breastfeeding among primiparous women. Journal of Midwifery & Woman’s Health 45: 227–237.

    Article  Google Scholar 

  3. Bard KA (1995) Parenting in primates. In: Handbook of Parenting. Vol. 2, Biology and Ecology of Parenting (Bornstein MH, ed), 27–58. Mahwah, NJ: Erlbaum.

    Google Scholar 

  4. Boesch C, Boesch H (1984) Mental maps in chimpanzees: An analysis of hammer transports for nut cracking. Primates 25: 160–170.

    Article  Google Scholar 

  5. Cantrill R (2006) Influence of Naked Body Contact Between Mother and Newborn on Effective Breastfeeding. Doctoral dissertation, Griffith University, Queensland, Australia.

    Google Scholar 

  6. Cavalli-Sforza LL, Feldman MW (1981) Cultural Transmission and Evolution: A Quantitative Approach. Princeton, NJ: Princeton University Press.

    Google Scholar 

  7. Cutler WB, Preti G, Krieger A, Huggins GR, Garcia CR, Lawley HJ (1986) Human axillary secretions influence women’s menstrual cycles: The role of donor extract from men. Hormones and Behavior 20: 463–473.

    Article  Google Scholar 

  8. Darwin C (1871) The Descent of Man, and Selection in Relation to Sex, Vol. 2. London: John Murray.

    Book  Google Scholar 

  9. De Waal F (1995) Bonobo sex and society: The behavior of a close relative challenges assumptions about male supremacy in human evolution. Scientific American 272(3): 82–88.

    Article  Google Scholar 

  10. Frayer DW, Wolpoff MH (1985) Sexual dimorphism. Annual Review of Anthropology 14: 429–473.

    Article  Google Scholar 

  11. Gallup GG, Burch RL, Zappieri ML, Parvez RA, Stockwell ML, Davis JA (2003) The human penis as a semen displacement device. Evolution and Human Behavior 24: 277–289.

    Article  Google Scholar 

  12. Giles J (1994) A theory of love and sexual desire. Journal for the Theory of Social Behaviour 24: 339–357.

    Article  Google Scholar 

  13. Giles J (1999) Sartre, sexual desire, and relations with others. In: French Existentialism: Consciousness, Ethics, and Relations with Others (Giles J, ed), 155–174. Amsterdam: Rodopi.

    Google Scholar 

  14. Giles J (2004) The Nature of Sexual Desire. Westport, CT: Praeger.

    Google Scholar 

  15. Giles J (2006) Social constructionism and sexual desire. Journal for the Theory of Social Behaviour 36: 226–238.

    Article  Google Scholar 

  16. Giles J (2008) Sex hormones and sexual desire. Journal for the Theory of Social Behaviour 38: 45–66.

    Article  Google Scholar 

  17. Goodall J (1986) The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, MA: Harvard University Press.

    Google Scholar 

  18. Hardy A (1960) Was man more aquatic in the past? New Scientist 7: 642–645.

    Google Scholar 

  19. Harlow HF, Zimmermann RR (1958) The development of affectional responses in infant monkeys. Proceedings of the American Philosophical Society 102: 501–509.

    Google Scholar 

  20. Harris JR (2006) Parental selection: A third selection process in the evolution of human hairlessness and skin color. Medical Hypotheses 66: 1053–1059.

    Article  Google Scholar 

  21. Herbenick D, Schick V, Reece M, Sanders S, Fortenberry JD (2010) Pubic hair removal among women in the United States: Prevalence, methods, and characteristics. Journal of Sexual Medicine 7: 3322–3330.

    Article  Google Scholar 

  22. Hewes GW (1961) Food transport and the origin of hominin bipedalism. American Anthropologist 63: 687–710.

    Article  Google Scholar 

  23. Hunt M (1974) Sexual Behavior in the 1970s. Chicago: Playboy Press.

    Google Scholar 

  24. Hupka RB (1981) Cultural determinants of jealousy. Alternative Lifestyles 4: 310–356.

    Article  Google Scholar 

  25. Islam MA, Feeroz MM (1992) Ecology of Hoolock gibbon of Bangladesh. Primates 33: 451–464.

    Article  Google Scholar 

  26. Jablonski NG (2010) The naked truth. Scientific American (February): 42–49.

  27. Jolly C (1970) The seed-eaters: A new model of hominin differentiation based on a baboon analogy. Man 5: 5–28.

    Article  Google Scholar 

  28. Kaplan G, Rogers LJ (1999) The Orang-Utans. London: Allen and Unwin.

    Google Scholar 

  29. Kasai K (1995) Nihon Josei no Gaiseishokuki (External Genitalia of Japanese Females). Tokyo: Free Press.

    Google Scholar 

  30. Kingston JD, Marino BD, Hill A (1994) Isotopic evidence of neogene hominin paleoenvironments in Kenya Rift Valley. Science 264: 955–959.

    Article  Google Scholar 

  31. Kittler R, Kayser M, Stoneking M (2003) Molecular evolution of Pediculus humanus and the origin of clothing. Current Biology 13: 1414–1417.

    Article  Google Scholar 

  32. Lewis B, Jurmain R, Kilgore L (2010) Understanding Humans: Introduction to Physical Anthropology and Archaeology, 10th ed. Belmont, CA: Wadsworth.

    Google Scholar 

  33. Lindenfors P, Gittleman JL, Jones KE (2007) Sexual size dimorphism in mammals. In: Sex, Size, and Gender Roles: Evolutionary Studies of Sexual Size Dimorphism (Fairbairn DJ, Blanckenhorn WU, Székely T, eds), 16–26. Oxford: Oxford University Press.

    Google Scholar 

  34. Miller SL, Maner JK (2009) Scent of a woman: Men’s testosterone responses to olfactory ovulation cues. Psychological Science 1: 276–283.

    Google Scholar 

  35. Mitani JC (1984) The behavioral regulation of monogamy in gibbons Hylobates muelleri. Behavioral Ecology and Sociobiology 15: 225–230.

    Article  Google Scholar 

  36. Montagu A (1972) Touching: The Human Significance of the Skin. New York: Harper and Row.

    Google Scholar 

  37. Moore ER, Anderson GC, Bergman N (2007) Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane Database of Systematic Reviews 3: CD003519. DOI:10.1002/14651858.CD003519.pub2

    Google Scholar 

  38. Morgan E (1997) The Aquatic Ape Hypothesis. London: Souvenir Press.

    Google Scholar 

  39. Oakley K (1961) On man’s use of fire, with comments on tool-making and hunting. In: Social Life of Early Man (Washburn SL, ed), 176–193. Chicago: Aldine.

    Google Scholar 

  40. Pagel M, Bodmer W (2003) A naked ape would have fewer parasites. Proceedings of the Royal Society of London B 270: S117–S119.

    Article  Google Scholar 

  41. Post PW, Szabó G, Keeling ME (1975) A quantitative and morphological study of the pigmentary system of the chimpanzee with the light and electron microscope. Amercian Journal of Physical Anthropology 43: 435–444.

    Article  Google Scholar 

  42. Reichard U, Sommer V (1997) Group encounters in wild gibbons (Hylobates lar): Agonism, affiliation, and the concept of infanticide. Behaviour 134: 1135–1174.

    Article  Google Scholar 

  43. Rogers AR, Iltis D, Wooding S (2004) Genetic variation at the MC1R locus and the time since loss of human body hair. Current Anthropology 45: 105–108.

    Article  Google Scholar 

  44. SØrensen B (2009) Energy use by Eem Neanderthals. Journal of Archaeological Science 36: 2201–2205.

    Article  Google Scholar 

  45. Stoddart DM (1990) The Scented Ape: The Biology and Culture of Human Odour. Cambridge: Cambridge University Press.

    Google Scholar 

  46. van Schaik CP, Hodges JK, Nunn CL (2000) Paternity confusion and the ovarian cycles of female primates. In: Infanticide by Males and its Implications (van Schaik CP, ed) 361–387. Cambridge: Cambridge University Press.

    Google Scholar 

  47. Widström AM, Ransjo-Arvidson AB, Christensson K, Matthiesen AS, Winberg J, Uvnas-Moberg K (1987) Gastric suction in healthy newborn infants: Effects on circulation and developing feeding behaviour. Acta Paediatrica Scandinavica 76: 566–572.

    Article  Google Scholar 

  48. Wrangham R (2002) The cost of sexual attraction: Is there a trade off in female Pan between sex appeal and received coercion? In: Behavioural Diversity in Chimpanzees and Bonobos (Boesch C, Hohmann G, Marchant LF, eds), 204–215. Cambridge: Cambridge University Press.

    Google Scholar 

  49. Wyart C, Webster WW, Chen JH, Wilson SR, McClary A, Khan RM, Sobel N (2007) Smelling a single component of male sweat alters levels of cortisol in women. Journal of Neuroscience 27: 1261–1265.

    Article  Google Scholar 

  50. Wyatt D (2003) Pheromones and Animal Behaviour: Communication by Smell and Taste. Cambridge: Cambridge University Press.

    Book  Google Scholar 

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Correspondence to James Giles.

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Giles, J. Naked Love: The Evolution of Human Hairlessness. Biol Theory 5, 326–336 (2010). https://doi.org/10.1162/BIOT_a_00062

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Keywords

  • bipedalism
  • breast-feeding
  • evolution
  • hairlessness
  • maternal selection
  • romantic love
  • sexual pleasure
  • sexual selection
  • skin-to-skin contact