Subjects identify the face on the left as female and the face on the right as male. The only difference is the lightness of the skin. Richard Russell, Sinha Laboratory for Vision Research, MIT.
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“The fair sex” is paler than men, who conversely are ruddier and browner than women. This sex difference seems to play a role in gender recognition and in relations between men and women, particularly in female response to darker male skin.
Women
are universally the fair sex. They are paler than men, who conversely are
ruddier and browner (Frost, 2010; Frost, 2023; van den Berghe and
Frost, 1986). This sex difference is due to the differing ways the skin’s
pigments—melanin, hemoglobin, carotene—interact with the sex hormones, either
androgens in men or estrogens in women. A hormonal cause has been shown by
studies of normal, castrated, and ovariectomized individuals, by studies of
skin reflectance at puberty, and by studies of digit ratios (Edwards and
Duntley, 1939; Edwards et al., 1941; Edwards and Duntley, 1949; Frost,
1988; van den Berghe and Frost, 1986; Manning et al., 2004).
Gender
recognition
This
sex difference is used subconsciously to recognize male and female faces
(Frost, 2011; Russell, 2003; Russell, 2009; Russell,
2010; Russell et al., 2006; Semin et al., 2018).
Specifically,
gender is identified from two aspects of facial color:
·
hue
(men are ruddier and browner)
·
brightness
(facial skin is lighter in women and contrasts more with the darker lip/eye
area).
Hue
provides the observer with a fast channel for gender recognition. If a face is
too far away or the lighting too dim, the observer will switch to the slower
but more accurate channel of brightness (Dupuis-Roy et al.,
2009; Dupuis-Roy et al., 2019; Jones et al., 2015; Nestor and
Tarr, 2008a; Nestor and Tarr 2008b; Tarr et al. 2001; Tarr,
Rossion, and Doerschner, 2002). We thus perceive skin color through the lens of
a mental algorithm that arose for gender recognition. This algorithm may
explain why lighter skin seems more feminine and darker skin more masculine
(Semin et al., 2018).
Male-female
relations
The
differing complexions of men and women play a role not only in gender
recognition but also in relations between men and women. In particular, it
seems to play a role in attraction by women to men.
In
one study, women were asked to optimize the attractiveness of facial pictures
by varying the skin's darkness and ruddiness. They made the male faces darker
and ruddier than the female faces (Carrito et al., 2016). In another study,
women were asked to rate different levels of male ruddiness. They associated
high levels with aggression, medium levels with dominance, and low levels with
attractiveness. Unlike the participants of the first study, they may have
understood the term “attractive” in an aesthetic or even feminine sense
(Stephen et al., 2012).
Female
attraction to darker, ruddier male skin seems to be mediated by the level of
estrogen in brain tissues. This estrogenic effect is shown by two studies of
women at different phases of their menstrual cycle and by a study of preschool
children:
·
Women
were shown pairs of facial pictures that differed slightly in the lightness of
the skin, and they were asked to choose the most pleasing one. When male faces
were shown, the darker one was more strongly preferred by those women who were
in the first two-thirds of their menstrual cycle than by those in the last
third. During the first two-thirds of the cycle, the level of estrogen is high
in relation to the level of progesterone (which acts as an anti-estrogen).
During the last third, the ratio is reversed: the level of estrogen is low in
relation to the level of progesterone. There was no cyclical effect among women
judging female faces or taking oral contraceptives (Frost, 1994).
·
Women
had their brain activity measured by MRI while viewing pictures of male faces.
Their brains showed a stronger response to masculinized male faces than to
feminized ones, and the strength of their response correlated with the level of
estrogen across the menstrual cycle. In a personal communication, the lead
author stated that the faces had been masculinized by making them darker and
more robust in shape (Rupp et al., 2009).
·
Preschool
boys and girls were presented with two dolls that differed slightly in skin
color and asked to choose the “nicer” one. Their choices were recorded, as were
measurements of their body mass index and their subcutaneous fat. Doll choice
did not differ by sex. But it did differ by adiposity. Among children less than
three years old, those who chose the darker doll had significantly more body
fat than those who chose the lighter doll. In that age range, estrogen is
produced mostly in the fatty tissues, which contain an enzyme (aromatase) that
converts an androgen (androstenedione) into an estrogen (estrone) (Baird,
1976; Frost, 1989).
The doll on the right is slightly darker and ruddier than the one on the left. Among children below three years of age, those who chose the darker doll had significantly more body fat than those who chose the lighter doll. At such ages, estrogen is produced mainly in the body’s fatty tissues.
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In
other doll studies, boys and girls have similar preferences up to six years of
age (Renninger and Williams, 1966; Williams and Roberson,
1967; Williams and Rousseau, 1971). At older ages, male and female
preferences begin to diverge. When a group of American children, 3 to 8 years
of age, were presented with a white-faced puppet and a brown-faced one, the
latter puppet was more often chosen by girls than by boys, this finding being
as true for Euro-American children as for African American children (Asher and
Allen, 1969).
There
are fewer controlled studies of male response to lighter female skin. It has
been argued that the lighter skin of women mimics that of infants, whose
pinkish color is especially noticeable in darker-skinned populations and,
apparently, in other primate species. It seems to identify the primate infant
as a vulnerable being in need of protection (Alley, 1980; Booth,
1962; Jay, 1962).
In
our species, the adult female may have evolved a lighter complexion as a means
to tap into the same behavioral response, the aim being not so much to increase
male sexual arousal as to reduce male aggressiveness and stimulate feelings of
care (Frost, 2010, p. 131-136; Frost, 2023; Guthrie, 1970).
Proposed
study
First
research aim: expand on Rupp et al. (2009) by using brain MRI to
measure how women respond to male facial hue and luminosity in relation to the
levels of estrogen and progesterone across the menstrual cycle. Male facial
photos would be altered to produce different degrees of brownness, redness, and
brightness.
Second
research aim: repeat the doll study of Frost (1989) with direct
measures of estrogen and androgen levels in preschool children. This may be
difficult, given the low hormonal levels of early childhood (Baird,
1976; Klein et al., 1994).
References
Alley,
T. R. (1980). Infantile colouration as an elicitor of caretaking behaviour in
Old World primates. Primates 21(3):
416-429. https://doi.org/10.1007/BF02390470
Asher,
S.R. and Allen, V.L. (1969). Racial preference and social comparison
processes. Journal of Social
Issues 25(1): 157-166. https://doi.org/10.1111/j.1540-4560.1969.tb02584.x
Baird,
D.T. (1976). Oestrogens in clinical practice. In: J.A. Loraine and E. Trevor
Bell (eds.) Hormone assays and their
clinical application (p. 408). Edinburgh: Churchill Livingstone.
Booth,
C. (1962). Some observations on behavior of Cercopithecus monkeys. Annals of the New York Academy of Sciences 102(2):
477-487. https://doi.org/10.1111/j.1749-6632.1962.tb13654.x
Bruce,
V., and Langton, S. (1994). The use of pigmentation and shading information in
recognising the sex and identities of faces. Perception 23(7): 803-822. http://dx.doi.org/10.1068/p230803
Carrito,
M.L., dos Santos, I.M.B., Lefevre, C.E., Whitehead, R.D., da Silva, C.F., and
Perrett, D.I. (2016). The role of sexually dimorphic skin colour and shape in
attractiveness of male faces. Evolution
and Human Behavior 37(2): 125-133. https://doi.org/10.1016/j.evolhumbehav.2015.09.006
Dupuis-Roy,
N., Faghel-Soubeyrand, S., and Gosselin, F. (2019). Time course of the use of
chromatic and achromatic facial information for sex categorization. Vision Research 157: 36-43. https://doi.org/10.1016/j.visres.2018.08.004
Dupuis-Roy,
N., Fortin, I., Fiset, D., and Gosselin, F. (2009). Uncovering gender
discrimination cues in a realistic setting. Journal of Vision 9(2): 10, 1-8. https://doi.org/10.1167/9.2.10
Edwards,
E.A., and Duntley, S.Q. (1939). The pigments and color of living human
skin. American Journal of Anatomy 65(1):
1-33. https://doi.org/10.1002/aja.1000650102
Edwards,
E.A., and Duntley, S.Q. (1949). Cutaneous vascular changes in women in
reference to the menstrual cycle and ovariectomy. American Journal of Obstetrics & Gynecology 57(3):
501-509. https://doi.org/10.1016/0002-9378(49)90235-5
Edwards,
E.A., Hamilton, J.B., Duntley, S.Q., and Hubert, G. (1941). Cutaneous vascular
and pigmentary changes in castrate and eunuchoid men. Endocrinology 28(1): 119-128. https://doi.org/10.1210/endo-28-1-119
Frost,
P. (1988). Human skin color: A possible relationship between its sexual
dimorphism and its social perception. Perspectives
in Biology and Medicine 32(1): 38-58. https://doi.org/10.1353/pbm.1988.0010
Frost,
P. (1989). Human skin color: the sexual differentiation of its social
perception. Mankind Quarterly 30:
3-16. http://doi.org/10.46469/mq.1989.30.1.1
Frost,
P. (1994). Preference for darker faces in photographs at different phases of
the menstrual cycle: Preliminary assessment of evidence for a hormonal
relationship. Perceptual and Motor
Skills 79(1): 507-14. https://doi.org/10.2466/pms.1994.79.1.507
Frost,
P. (2010). Femmes claires, hommes foncés. Les racines oubliées du colorisme. Quebec City: Les Presses de l'Université Laval, 202
p. https://www.pulaval.com/livres/femmes-claires-hommes-fonces-les-racines-oubliees-du-colorisme
Frost,
P. (2011). Hue and luminosity of human skin: a visual cue for gender
recognition and other mental tasks. Human
Ethology Bulletin 26(2): 25-34. https://www.researchgate.net/publication/256296588_Hue_and_luminosity_of_human_skin_a_visual_cue_for_gender_recognition_and_other_mental_tasks
Frost,
P. (2023). The original meaning of skin color. Aporia Magazine, February 7.
Guthrie,
R.D. (1970). Evolution of human threat display organs. In T. Dobzhansky, M.K.
Hecht, and W.C. Steere (Eds.) Evolutionary
Biology 4: 257-302. New York: Appleton-Century Crofts.
Hill,
H., V. Bruce, and Akamatsu, S. (1995). Perceiving the sex and race of faces:
The role of shape and colour. Proceedings
of the Royal Society B: Biological Sciences 261(1362): 367-373. https://doi.org/10.1098/rspb.1995.0161
Hill,
R., and Barton, R. (2005). Red enhances human performance in contests. Nature 435: 293. https://doi.org/10.1038/435293a
Jay,
P.C. (1962). Aspects of maternal behavior among langurs. Annals of the New York Academy of Sciences 102(2):
468-476. https://doi.org/10.1111/j.1749-6632.1962.tb13653.x
Jones,
A.L., Russell, R., and Ward, R. (2015). Cosmetics alter biologically-based
factors of beauty: evidence from facial contrast. Evolutionary Psychology 13(1): https://doi.org/10.1177%2F147470491501300113
Klein,
K.O., Baron, J., Colli, M.J., McDonnell, D.P., and Cutler, G.B. Jr. (1994).
Estrogen levels in childhood determined by an ultrasensitive recombinant cell
bioassay. Journal of Clinical
Investigation 94(6): 2475-2480. https://doi.org/10.1172/JCI117616
Manning,
J.T., Bundred, P.E., and Mather, F.M. (2004). Second to fourth digit ratio,
sexual selection, and skin colour. Evolution
and Human Behavior 25(1): 38-50. https://doi.org/10.1016/s1090-5138(03)00082-5
Nestor,
A., and Tarr, M.J. (2008a). The segmental structure of faces and its use in
gender recognition. Journal of
Vision 8(7): 7, 1-12, https://doi.org/10.1167/8.7.7
Nestor,
A., and Tarr, M.J. (2008b). Gender recognition of human faces using
color. Psychological Science 19(12):
1242-1246. https://doi.org/10.1111/j.1467-9280.2008.02232.x
Renninger,
C.A. and Williams, J.E. (1966). Black-white color connotations and racial
awareness in preschool children. Perceptual
and Motor Skills 22(3): 771-785. https://doi.org/10.2466/pms.1966.22.3.771
Rupp,
H.A., James, T.W., Ketterson, E.D., Sengelaub, D.R., Janssen, E., and Heiman,
J.R. (2009). Neural activation in women in response to masculinized male faces:
mediation by hormones and psychosexual factors. Evolution and Human Behavior 30(1): 1-10. https://doi.org/10.1016/j.evolhumbehav.2008.08.006
Russell,
R. (2003). Sex, beauty, and the relative luminance of facial features. Perception 32(9): 1093-1107. http://dx.doi.org/10.1068/p5101
Russell,
R. (2009). A sex difference in facial pigmentation and its exaggeration by
cosmetics. Perception 38(8):
1211-1219. https://doi.org/10.1068/p6331
Russell,
R. (2010). Why cosmetics work. In: R.B. Adams Jr., N. Ambady, K. Nakayama, and
S. Shimojo (eds.) The Science of
Social Vision, (pp. 186-203). New York: Oxford.
Russell,
R., Sinha, P., Biederman, I., and Nederhouser, M. (2006). Is pigmentation
important for face recognition? Evidence from contrast negation. Perception 35: 749-759. https://doi.org/10.1068%2Fp5490
Semin,
G.R., Palma, T., Acartürk, C., and Dziuba, A. (2018). Gender is not simply a
matter of black and white, or is it? Philosophical
Transactions of the Royal Society B Biological Sciences 373(1752):20170126. https://doi.org/10.1098/rstb.2017.0126
Siiteri,
P.K. and MacDonald, P.C. (1973). Role of extraglandular estrogen in human
endocrinology. In: S.R. Geiger (ed.), Handbook
of Physiology, vol. II, Part 1, (pp. 615-629). Washington D.C.: American
Physiology Society, Section 7.
Stephen,
I.D., Oldham, F.H., Perrett, D.I., and Barton, R.A. (2012). Redness enhances
perceived aggression, dominance and attractiveness in men's faces. Evolutionary Psychology 10(3). https://doi.org/10.1177%2F147470491201000312
Tarr,
M.J., Kersten, D., Cheng, Y., and Rossion, B. (2001). It's Pat! Sexing faces
using only red and green. Journal of
Vision 1(3): 337, 337a. https://doi.org/10.1167/1.3.337
Tarr,
M. J., Rossion, B., and Doerschner, K. (2002). Men are from Mars, women are
from Venus: Behavioral and neural correlates of face sexing using color. Journal of Vision 2(7): 598,
598a, https://doi.org/10.1167/2.7.598
Trivers,
R., Manning, J., and Jacobson, A. (2006). A longitudinal study of digit ratio
(2D:4D) and other finger ratios in Jamaican children. Hormones and Behavior 49(2): 150-156. https://doi.org/10.1016/j.yhbeh.2005.05.023
van
den Berghe, P. L. and P. Frost. (1986). Skin color preference, sexual
dimorphism, and sexual selection: A case of gene-culture co-evolution? Ethnic and Racial Studies 9(1):
87-113. https://doi.org/10.1080/01419870.1986.9993516
Williams,
J.E. and Roberson, J.K. (1967). A method for assessing racial attitudes in
preschool children. Educational and
Psychological Measurement 27(3): 671-689. https://doi.org/10.1177/001316446702700310
Williams, J.E. and Rousseau, C.A. (1971). Evaluation and identification responses of Negro preschoolers to the colors black and white. Perceptual and Motor Skills 33(2): 587-599. https://doi.org/10.2466/pms.1971.33.2.587
