Abstract
Unlike other apes, human females’ breasts develop before first pregnancy and are permanently enlarged. Evidence suggests breasts act as signals to males but the critical data required to confirm this are lacking. These facts have led to a number of hypotheses about the evolutionary and adaptive significance of the human breast which fall into two groups. Those that address the presence of breasts in humans are (a) that they act as releasers of male sexual behaviour, (b) that they enable females to hide their reproductive condition, and (c) that they allow infants to nurse from their mother’s hip. Those that address variability in breast size are (d) that large breasts indicate lactational potential, (e) ability of mothers to invest prenatally in offspring, (f) mother’s fecundity, and (g) her longevity. Each hypothesis is reviewed and evaluated using logical or empirical arguments. Possible ways in which the adaptive significance of human breasts can be determined in contemporary populations are outlined.
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References
Alexander R. D. &Noonan K. M., 1979.Concealment of ovulation, parental care, and human social evolution. In (N. A. Chagnon & W. Irons, Eds). Evolutionary Biology and Human Social Behavior: An Anthropological Perspective, pp. 436–453. North Scituate, Mass.; Duxbury Press.
Altmann J., 1980.Baboon Mothers and Infants. Cambridge, Mass: Harvard University Press.
Borgerhoff Mulder M., 1987.Kipsigis bridewealth payments. In (L. L. Betzig, M. Borgerhoff Mulder & P. W. Turke, Eds). Human Reproductive Behaviour: A Darwinian Perspective, Cambridge: Cambridge University Press.
Broude G. E. &Grene S. J., 1976.Crosscultural codes on twenty sexual attitudes and practices. Ethnology 15: 410–429.
Campaigne B. N., Katch V. L., Freedson P. &Sady S., 1979.Measurement of breast volume in females: description of a reliable method. Annals of Human Biology 6: 363–367.
Campbell B. G., 1974.Human Evolution, 2nd edition. Chicago: Aldine.
Cant J. G. H., 1981.Hypothesis for the evolution of human breasts and buttocks. American Naturalist, 117: 199–204.
Caro T. M. & Borgerhoff Mulder M. (in press).The problem of adaptation in the study of human behaviour. Ethology and Sociobiology.
Clutton-Brock T. H., Albon S. D. &Guiness F. E., 1987.Reproductive success in male and female re deer. In (T. H. Clutton-Brock, Ed). Reproductive Success. Chicago: Chicago University Press.
Cook M. &McHenry R., 1978.Sexual Attraction. Oxford: Pergamon Press.
Cowie A. T., 1984.Lactation. In (C. R. Austin & R. V. Short, Eds). Hormonal Control of Reproduction, 2nd edition pp. 195–231. Cambridge: Cambridge University Press.
Crook J. H., 1972.Sexual selection, dimorphism and social organisation in the primates. In (B. Campbell, Ed.). Sexual Selection and the Descent of Man 1871–1971 pp. 231–281. Chicago: Aldine.
Crook J. H. &Gartlan J. S., 1966.Evolution of primate societies. Nature, 210: 1200–1203.
Davies N. B., 1982.Behaviour and competition for scarce resources. In (Kings College Sociobiology Group, Ed.). Current Problems in Sociobiology, pp. 363–380. Cambridge: Cambridge University Press.
Devi M. R., Kumari J. R. &Srikumari C. R., 1985.Fertility and mortality differences in relation to maternal body size. Annals of Human Biology, 12: 479–484.
Eibil-Eibesfeldt I., 1970.Ethology: the Biology of Behavior. New York: Holt, Rinehart & Winston.
Fisher R. A., 1958.The Genetical Theory of Natural Selection. New York: Dover.
Ford C. S. &Breach F. A., 1952.Patterns of Sexual Behaviour. London: Methuen.
Frisch R. E., 1975.Demographic implications of the biological determinants of female fecundity. Social Biology, 22: 17–22.
Frisch R. E., 1978a.Menarche and fatness: reexamination of the critical body composition hypothesis. Science, 200: 1509–1513.
Frisch R. E., 1978b.Population, food intake, and fertility. Science, 199: 22–30.
Frisch R. E., 1983.Reply to Anderson. Current Anthropology, 24: 32.
Frisch R. E. &McArthur J. W., 1974.Menstrual cycles: fatness as a determinant of minimum weight necessary for their maintenance or onset. Science, 185: 949–951.
Gallup G. G. Jr., 1982.Permanent breast enlargement in human females: a sociobiological analysis. Journal of Human Evolution, 11: 597–601.
Gallup G. G. Jr., 1986.Unique features of human sexuality in the context of evolution. In (D. Byrne & K. Kelley, Eds). Alternative Approaches to the Study of Sexual Behavior, pp. 13–42. New Jersey: Lawrence Erlabum.
Goodhart C. B., 1964.A biological view of toplessness. New Scientist, 23: (407), 558–560.
Gould S. J. &Vrba E. S., 1982.Exaption — a missing term in the science of form. Paleobiology, 8: 3–15.
Graham C. A. &Mc. Grew W. C., 1980.Menstrual synchrony in female undergraduates living on a coeducational campus. Psychoneuroendocrinology, 5: 245–252.
Gunther M., 1955.Instinct and the nursing couple. Lancet 1955: 575–578.
Hamilton C. E. &Rankin J., 1975.Changes in volume of the breast during the menstrual cycle. British Journal of Surgery, 62: 660–669.
Harcourt A. H., Harvey P. H., Larson S. G. &Short R. V., 1981.Testis weight, body and breeding system in primates. Nature, 293: 55–57.
Hartmann P. E., Rattigan S., Prosser C. G., Saint L. &Arthur P. G., 1984.Human lactation: back to nature. Symposium of the Zoological Society of London, 51: 337–368.
Hinde R. A., 1975.The concept of function. In (G. Baerends, C. Beer & A. Manning, Eds). Function and Evolution in Behaviour, pp. 3–15. Oxford: Clarendon.
Hollander X., 1985. Penthouse Magazine, 20: (3), 131.
Hytten F. E., 1954.Clinical and chemical studies in human lactation VI. The functional capacity of the breast. British Medical Journal, 1: 912–915.
Hytten F. E. &Thomson A. M., 1965.Pregnancy, childbirth and lactation. In (O. G. Edholm & A. L. Bacharach, Eds). The Physiology of Human Survival, pp. 327–350. London: Academic Press.
Kano T., 1980.Social behavior of wild pigmy chimpanzees (Pan paniscus) of Wamba: a preliminary report. Journal of Human Evolution, 9: 243–260.
Katch V. L., Campaigne B, Freedson P., Sady S., Katch F. I. &Behnke A. R., 1980.Contribution of breast volume and weight to body fat distribution in females. American Journal of Physical Anthropology, 53: 93–100.
Kleine C. L. &Staneski R. A., 1980.First impressions of female bust size. Journal of Social Psychology, 110: 123–134.
Konner M. &Worthman C., 1980.Nursing frequency, gonadal function, and birth spacing among! Kung hunter-gatherers. Sicence, 207: 788–791.
Kuttner R. E., 1975.On infant convenience and female breast form.American Naturalist, 109: 596.
Lamb M. E., Pleck J. H., Charnov E. L. &Levine J. A. 1985.Paternal behavior in humans. American Zoologist, 25: 883–894.
Le Blanc S. A. &Barnes E., 1974.On the adaptive significance of the human breast. American Naturalist, 108: 577–578.
Lohman T. G., 1981.Skinfolds and body density and their relation to fatness: a review. Human Biology, 53: 181–225.
Lovejoi C. O., 1981.The origin of man. Science, 211: 341–350.
Malina R. M., 1983.Menarche in atheletes: a synthesis and hypothesis. Annals of Human Biology, 10: 1–24.
Marshall W. A., 1970.Sex differences at puberty. Journal of Biosocial Science suppl., 2: 31–41.
Mason W. A., 1965.The social development of monkeys and apes. In (I. DeVore, Ed). Primate Behavior: Field Studies of Monkeys and Apes. pp. 514–543. New York: Holt, Rinehart & Winston.
Masters W. H. &Johnson V. E., 1966.Human Sexual Response. Londo: J. & E. Churchill.
Maynard Smith J., 1977.Parental investment: a prospective analysis. Animal Behaviour, 25: 1–9.
Morgan E. 1972.The Descent of Woman, New York: Stein & Day.
Morris D. 1967.The Naked Ape. London: Jonathan Cape.
Munn C. A., 1986.Birds that ‘cry wolf’. Nature, 319: 143–145.
Nassar A. M. &Smith R. E., 1975.Menstrual variations in thermal properties of the human breast. Journal of Applied Physiology, 39: 806–811.
Peaker M., Vernon R. G. &Knight C. H., 1984.Physiological Strategies in Lactation. Zoological Society of London. London: Academic Press.
Pond C. M., 1984.Physiological and ecological importance of energy storage in the evolution of lactation: evidence for a common pattern of anatomical organisation of adipose tissue in mammals. Symposium of the Zoological Society of London, 51: 1–32.
Prentice A. M., Paul A. A., Prentice A., Black A. E., Cole T. J. &Withehead R. G., 1986.Crosscultural differences in lactational performance. In (M. Hamosh & A. S. Goldman, Eds) Human Lactation — Maternal and Environmental factors. pp. 13–44. New York: Plenum Pubbl. Corp. October 1985.
«S. J. L.», 1986.Guardian Newspaper, January 15th, p. 22.
Salazar H. &Tobon H., 1974.Morphological changes in the mammary gland during development, pregnancy, and lactation. In (J. B. Josimovich, M. Reynolds & E. Cobo, Eds). Lactogenic Hormones, Fetal Nutrition and Lactation p. 221. New York: Wiley.
Davard R., Bouchard C., LeBlanc C. &Tremblay A., 1983.Familial resemblance in fatness indicators. Annals of Human Biology, 10: 111–118.
Schell L. M. &Hodges D. C., 1985.Variation in size at birth and cigarette smoking during pregnancy. American Journal of Physical Anthropology, 68: 549–554.
Schmidt G. &Sigusch V., 1970.Sex differences in responses to psychosexual stimulation by films and slides. Journal of Sex Research, 6: 268–283.
Schort R. V., 1976.The evolution of human reproduction. Proceedings of the Royal Society of London B., 195: 3–24.
Short R. V., 1979.Sexual selection and its component parts, somatic and genital selection, as illustrated by man and the great apes. Advances in the Study of Behavior, 9: 131–158.
Short R. V. &Drife J. O., 1977.The aetiology of mammary cancer in man and animals. Symposium of the Zoological Society of London, 41: 211–230.
Simpson M. J. A., 1978.Tactile experience and sexual behaviour: aspects of development with special reference to primates. In (J. B. Hutchison, Ed). Biological Determinants of Sexual Behaviour. pp. 785–807. Chichester: John Wiley & Sons.
Smith R. L., 1984.Human sperm competition. In (R. L. Smith, Ed). Sperm Competition and the Evolution of Animal Mating Systems. pp. 601–659. Orlando, Florida: Academic Press.
Symons D., 1979.The Evolution of Human Sexuality. Oxford: Oxford University Press.
Tinbergen N.On aims and methods of ethology. Zeitschrift fur Tierpsychologie, 20: 410–463.
Trivers R. L., 1972.Parental investment and sexual selection. In (B. Campbell, Ed). Sexual Selection and the Descent of Man 1871–1971. pp. 136–179. Chicago: Aldine.
Trivers R., 1985.Social Evolution. Menlo Park, California: Benjamin/Cummings.
Trussel J., 1978.Menarche and fatness: reexamination of the critical body composition hypothesis. Science, 200: 1506–1509.
Turke P. W., 1984.Effects of ovulatory concealment and synchrony on protohominid mating systems and parental roles. Ethology and Sociobiology, 5: 33–44.
Weiss E., 1975.The Female Breast. New York: Bantam books.
Wickler W., 1972.The Sexual Code. Garden City, New York: Doubleday.
Wiggins J. S., Wiggins N. &Conger J. C., 1968.Correlates of heterosexual somatic preference. Journal of Personality and Social Psychology, 10: 82–90.
Williams G. C., 1966.Adaptation and Natural Selection. Princeton: Princeton University Press.
Witten D. M., 1971.The Breast: An Atlas of Tumor Radiology. Yearbook Medical Publishers Inc.
Wood J. W., Lai D., Johnson P. L., Campbell K. L. &Maslar I. A., 1985.Lactation and birth spacing in hihgland New Guinea. Journal of Biosocial Sciences suppl., 9: 159–173.
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Caro, T.M. Human breasts: Unsupported hypotheses reviewed. Hum. Evol. 2, 271–282 (1987). https://doi.org/10.1007/BF03016112
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DOI: https://doi.org/10.1007/BF03016112