Behavioral Ecology
doi:10.1093/beheco/arp206
Advance Access publication 29 January 2010
Preference for human male body hair changes
across the menstrual cycle and menopause
Markus J. Rantala, Mari Pölkki, and Liisa M. Rantala
Department of Biology, Section of Ecology, University of Turku, FI-20014 Turku, Finland
It has commonly been considered that women’s preference with regard to male body hair changes over the years according to
fashion and is influenced by the media. Experimental evidence, however, is currently lacking. We examined the effect of male
torso hairiness on Finnish women’s attractiveness ratings by presenting pictures of male torsos before and after the removal of
body hair. We found that the women’s preferences correlated strongly with the hairiness of their current partners, suggesting
that body hair may play a role in actual mate choice. We also found that when the women’s fertility was at its highest, they
preferred males with less body hair and that postmenopausal wosmen demonstrated stronger preferences relating to male
body hair than did premenopausal women. Our study suggest that in the fertile period of their cycle, Finnish women prefer
more the trait that is the current Western ideal of male beauty (hairlessness) than the trait that is traditionally (albeit incorrectly) seen as a symbol of high testosterone levels and masculinity. Thus, it seems that the phase of the menstrual cycle may
affect the strength and direction of female preference even for traits that are not ‘‘good genes’’ indicators and whose
preference may be culturally based. Interestingly, the hairiness of the women’s fathers correlated positively with that of their
current mates. This suggests that women’s preferences as to male hairiness may be partly the result of sexual imprinting on
paternal body hair and/or that this preference is heritable. Key words: body hairs, homo sapiens, mate choice, sexual selection. [Behav Ecol 21:419–423 (2010)]
ecent studies testing sexual preferences in women have
found that women’s preferences for male traits change
across the menstrual cycle (reviewed in Gangestad and
Thornhill 2008). In the fertile (late follicular) phase of the
menstrual cycle, women have been found to have an increased
preference for facial masculinity (Frost 1994; Penton-Voak
et al. 1999; Penton-Voak and Perrett 2000; Johnston et al.
2001), vocal masculinity (Puts 2005; Feinberg et al. 2006),
dominant behavior (Gangestad et al. 2004), and for both taller and more masculine male bodies (Pawlowski and Jasienska
2005; Little et al. 2007). During this phase of the cycle, women
rate a male pheromone (Grammer 1993) and the scent of
dominance as more attractive (Havlicek et al. 2005). This
cyclic shift in preferences toward more masculine male traits
has been suggested to be potentially adaptive (e.g., PentonVoak et al. 1999). Masculinity in males is thought to be a
reliable indicator of heritable components of male quality
because testosterone reduces the strength of immune defense, so that only healthy males can maintain high testosterone levels (Folstad and Karter 1992). By preferring more
masculine and symmetrical men, women would be choosing
‘‘good genes’’ for their offspring (for review, see Gangestad
and Thornhill 2008; Jones et al. 2008). On the other hand,
masculinity is associated with testosterone, which in turn is
linked to marital instability and lower levels of attachment
in relationships (Booth and Dabbs 1993; Burnham et al.
2003), suggesting that masculine men provide less parental
investment. Thus, the cyclic shifts in women’s preferences
might enable women to maximize their fitness through extrapair copulation, potentially by shifting priorities between
indirect benefits in terms of good genes and direct benefits in
terms of parental investment (Penton-Voak et al. 1999).
R
Address correspondence to M.J. Rantala. E-mail: markus.rantala
@utu.fi.
Received 7 September 2009; revised 26 December 2009; accepted
29 December 2009.
The Author 2010. Published by Oxford University Press on behalf of
the International Society for Behavioral Ecology. All rights reserved.
For permissions, please e-mail: [email protected]
Although the cyclic shifts in women’s preferences on men’s
traits signaling genetic quality are well supported by experimental evidence, studies testing whether women’s preferences
on culturally based traits change with cycle are lacking. One
trait that can be affected by culture is the hirsuteness of male
body because hairs can be shaved if so desired (see, e.g.,
Boroughs et al. 2005). During puberty, many men grow trunk
hair on the chest and back. The thickness of trunk hair in
sexually mature men varies from the completely naked to
the almost completely hairy. Hairiness also varies considerably
between different human populations, which Darwin (1871)
suggested to be result of population differences in sexual preferences toward body hairs. Although there have been many
studies testing the impact of body proportions and fluctuating
asymmetry on the attractiveness of men’s bodies, almost all of
them have overlooked the contribution of body hair to attractiveness; most studies have used methods such as the 3D optical scanner to remove cues unrelated to body shape (e.g., Fan
et al. 2005; Brown et al. 2008). To our knowledge, the only
studies that have tested the role of trunk hair in the sexual
attractiveness of the male body have used outline drawings of
male figures (Dixson et al. 2003; Dixson, Dixson, Li, and
Anderson 2007; Dixson, Dixson, Morgan, and Anderson
2007). According to these studies, in England and Sri Lanka,
male trunk hair has a positive effect on women’s ratings of
attractiveness (Dixson et al. 2003). In Cameroon, body hair
had a positive effect on women’s attractiveness rating of males,
but the hairiest figure was not rated as the most attractive
(Dixson, Dixson, Morgan, and Anderson 2007). In contrast,
in China, women rated figures with no or little trunk hair as
the most attractive (Dixson, Dixson, Li, and Anderson 2007).
These studies suggest that body hair may play a role in mate
choice. Unfortunately, experimental studies using pictures of
real male bodies are currently lacking. There have also been
no studies with women to test which factors influence individual preferences for body hairiness and whether the hairiness
of the mate correlates with an individual woman’s preference
for body hair. It is commonly thought, however, that women’s
Behavioral Ecology
420
preference for male body hair changes across the years like
fashion and is influenced by the media (e.g., Luciano 2001;
Boroughs et al. 2005; Martins et al. 2008), although experimental evidence in this respect is still lacking. Because the
presence of body hair has traditionally been symbolic of masculinity and virility (e.g., Basow 1991; Basow and Braman 1998;
Tiggemann and Kenyon 1998; Toerien and Wilkinson 2003;
Tiggemann and Hodgson 2008), one might expect that women’s preferences for trunk hair would change with the menstrual cycle, although individual variation in hairiness does not
signal high testosterone levels in men (Burton et al. 1979;
Lookingbill et al. 1988,1991; Knussmann et al. 1992; Winkler
and Christiansen 1993). However, to our knowledge, there
have been no studies testing whether this is in fact the case.
The purpose of this study was to test whether male trunk hair
has any effect on the attractiveness of the image of the male
body and whether Finnish women’s preferences for male trunk
hair changes across the menstrual cycle, menopause, and age.
MATERIAL AND METHODS
Male participants
We recruited 20 Finnish males with visible trunk hair from the
University of Turku and Åbo Academy (aged 20–32 years, mean
age ¼ 25.7, standard deviation [SD] ¼ 3.7). The men received
a bottle of Koskenkorva vodka (Alko, Rajamäki, Finland) (0.33 l)
to compensate for the loss of their trunk hair and time. Frontand back-view photos of the males’ torsos were taken under symmetrical lighting conditions from a fixed distance of 200 cm
(Figure 1). The participants were asked to stand with their arms
relaxed at their sides. Immediately after the photo session, the
men were asked to shave their abdomen with a shaver, finishing
up with a razorblade and shaving cream. If needed, our laboratory assistants helped the men to complete the shaving. After
shaving, a new set of pictures was taken with an identical setup.
Female participants
In order to obtain as random and representative a sample of
Finnish women as possible, research assistants interviewed
women at shopping malls, in the street, at railway stations, in
the lobby of a university building, in the vicinity of a maternity
clinic, and in many other places with a high density of women in
the Finnish cities of Kemi, Oulu, Tampere, and Turku. The participants were presented with forced-choice paired image trials
of 20 males with and without body hair and then asked to choose
between the hairy and the completely naked (shaved) version of
the same body (Figure 1). To exclude the effect of skin irritation
caused by shaving, the photographs were black-and-white (13 3
10 cm). The trials were presented in random order. In each
trial, the participants were asked to choose the image that they
found sexually most attractive. After the trial, each woman was
given a brief questionnaire to fill out, asking about her age, the
ethnic origin of her mother and father, whether she was currently using contraceptive pills or another form of hormonal
contraception, the first day of her last menstrual period, the
typical length (in days) of her cycle, whether she was pregnant,
the age and hairiness of her boyfriend/husband’s body (scale
0–10, to help rating, the pictures of our male participants were
used as references), the age and hairiness of her father, and
whether her father was present during her early childhood.
A total of 552 women were interviewed for the experiment.
We excluded homosexual and bisexual women, women whose
parents were not Finnish, and women who were using oral contraceptives or any hormonal products that might affect their
mate choice. Likewise, women were excluded from the analysis
if they were unable to provide information about the typical
length of their menstrual cycle or the current phase of their
Figure 1
Paired photographs of a male body before (a) and after (b) the
removal of body hair. The photographs were presented to women in
the forced-choice trial.
cycle or if they had an abnormal or irregular length of the menstrual cycle. The total sample for statistical analysis consisted of
299 women (aged 15–69 years, mean age ¼ 34.5, SD ¼ 13.6).
Female raters were divided into 4 groups: 1) women in the
fertile phase of their cycle (N ¼ 62), 2) in the nonfertile phase
of their cycle (N ¼ 124), 3) postmenopausal women (N ¼ 60),
and 4) pregnant women (N ¼ 53). This method of assigning
women to groups according to fertility is based on the information that the luteal phase usually lasts 14 days and that the
fertile phase does not exceed 6 days (Dunson et al. 1999;
Wilcox et al. 2000). The method is commonly used in evolutionary psychological studies (see, e.g., Penton-Voak et al.
1999; Kuukasjärvi et al. 2004; Roberts et al. 2004, 2008;
Havlicek et al. 2005; Rantala et al. 2006; Little et al. 2007).
The study met the guidelines of the Ethical Board of the
University of Turku and was in accordance with the spirit of
the Helsinki Declaration of 1975.
Statistical analysis
The proportion of hairy pictures chosen was calculated for
each female participant by taking the number of hairy pictures
Rantala et al.
•
Body hair and sexual selection
Figure 2
Percentage of preferences for hairiness (6standard error of mean)
for premenopausal (N ¼ 186) and postmenopausal women (N ¼ 60).
picked from pairs and multiplying by 100 to give a percentage
value. The Kolmogorov–Smirnov test and visual inspection of
data suggested that women’s preferences for body hair were
normally distributed, so a parametric analysis was appropriate.
RESULTS
A one-sample t-test against no preference (50%, no preference) revealed that among premenopausal Finnish women,
body hair reduced the attractiveness of the male body (t ¼
24.37, degrees of freedom (df) ¼ 238, P , 0.001), whereas
among postmenopausal Finnish women, the opposite was true
(t ¼ 18,52, df ¼ 59, P , 0.001) (Figure 2). Women’s preference for body hair correlated strongly with the age of the
woman (r ¼ 0.424, N ¼ 299, P , 0.001): Older women preferred hairier men than younger women. As the groups differed considerably in age, analysis of covariance was used to
test differences in female preference for body hair, with age as
a covariate. There were significant differences in preferences
between groups (F ¼ 4.77, df ¼ 3, P ¼ 0.003) (Figure 3.). We
therefore employed Tukey’s post hoc tests to test the differences in estimated marginal means between treatments.
Women in the nonfertile phase of their cycle had a significantly higher preference for male body hair than those in the
fertile phase (mean difference 0.124, standard error [SE] ¼
0.44, P ¼ 0.005) (Figure 3). Postmenopausal women had
a stronger preference for male body hair than premenopausal
women who were either in the most fertile phase of their cycle
(mean difference 20.224, SE ¼ 0.042, P , 0.001) or in the
nonfertile phase. The preferences of pregnant women did not
differ from those of nonpregnant women in the nonfertile
phase of their cycle (mean difference 0.044, SE ¼ 0.042,
P ¼ 0.331). However, pregnant women did have a stronger
preference for body hair than women in the fertile phase of
their cycle (mean difference 20.351, SE ¼ 0.050, P , 0.001)
(Figure 3).
A woman’s preference for male body hair correlated strongly
with the hairiness of her current partner even when the woman’s age was used as a covariate (r ¼ 0.456, N ¼ 193, P , 0.001).
The hairiness of the current partner did not correlate with his
age (r ¼ 0.116, N ¼ 196, P ¼ 0.106). Interestingly, the hairiness of the woman’s father correlated with that of her current
partner (r ¼ 0.368, N ¼ 189, P , 0.001) as well as with her
preference for male body hair (r ¼ 0.132, N ¼ 290, P ¼ 0.024).
421
Figure 3
Percentage of preferences for hairiness (6standard error of mean)
for women in the low-fertile (N ¼ 124) and high-fertile (N ¼ 62)
phases of the menstrual cycle, postmenopausal (N ¼ 60), and
pregnant (N ¼ 53) women.
DISCUSSION
Interestingly, we found that the removal of body hair increased
the sexual attractiveness of the male body to Finnish premenopausal women. This result is consistent with the study by
Dixson, Morgan, and Anderson (2007), who found, using outline drawings of male figures, that Chinese women rated the
figures of men with the little or no hair as more attractive than
hairy ones. In contrast, British and Cameroon women preferred hairier male figures (Dixson et al. 2003, 2007). This
suggests the occurrence of population differences in women’s
preference for body hair, possibly explaining population differences in male trunk hair, just as Darwin (1871) suggested.
It is possible that population differences in women’s preference for body hair might be associated with the prevalence
of ectoparasites in the ancestral environment of population
because naked individuals would have been less susceptible
to ectoparasites (see Rantala 1999, 2007). On the other hand,
it is possible that the population differences in women’s
preferences are culturally based (see, e.g., Luciano 2001).
Our finding that a woman’s preference for body hair correlates strongly with the hairiness of her current boyfriend/husband suggests that body hair may play a role in actual mate
choice. Personal interviews with the women participating in
the experiment as raters revealed that many of them feel that
body hair plays an important role in mate choice. Many of the
women in fact had a very strong opinion as to the attractiveness
of body hair (personal observation).
Many recent studies have suggested that a woman’s preference with regard to male traits signaling masculinity changes
across the menstrual cycle and that during the most fertile period of their cycle, women prefer masculine male traits (traits
that signal high testosterone levels) (for review, see Gangestad
and Thornhill 2008). Interestingly, in this study, we found that
women preferred shaved male bodies at times when their
fertility was at its highest (in the follicular phase of their cycle). Likewise, pregnant women had a weaker aversion against
male body hair than women in the follicular phase of the
cycle. At first glance, one might conclude that our findings
contradict previous studies because hairier men are commonly thought to be more masculine (e.g., Basow 1991; Basow
and Braman 1998; Tiggemann and Kenyon 1998), probably
because of the occurrence of sex dimorphism in hairiness in
humans (see, e.g., Darwin 1871). Empirical studies, however,
Behavioral Ecology
422
do not support the hypothesis that hairy males are more masculine in biological sense. For example, hairiness has not
been found to correlate with traits that are associated with
high testosterone levels like masculinity of voice or masculine
body shape (e.g., Collins 2000). Likewise, individual variation
in chest hair growth has not been found to be correlated with
levels of circulating testosterone (Burton et al. 1979; Lookingbill et al. 1988, 1991; Knussmann et al. 1992). Furthermore,
Winkler and Christiansen (1993) found that !Kung San males
with more body hair had more estradiol in their blood, suggesting that hairy men might have more feminine hormonal
levels than less hairy men. In monogamous mammals, estrogen regulates parental behavior (Trainor and Marler 2002),
and men who become fathers have been found to have elevated estradiol levels (Berg and Wynne-Edwards 2001). Thus,
it might be adaptive for women to prefer hairier males during
the low-fertility phase of their cycle and while pregnant, if
individual variation in hairiness is associated with estradiol
levels also among Finnish men. Women’s preference for body
hair has been suggested to change over space and time (e.g.,
Boroughs et al. 2005). Thus, our study suggests that in the
fertile period of their cycle, Finnish women prefer more the
trait that is the current Western ideal of beauty (hairlessness)
(see Boroughs et al. 2005) than the trait that is traditionally
seen as a symbol of high testosterone levels and masculinity. It
seems that the phase of menstrual cycle may affect the
strength and direction of female preference even for traits
that are not good genes indicators and whose preference
may be culturally based.
It is possible that hairiness itself may not be the trait that
females are cueing in on. For example, body hair could mask
desirable male traits like muscles and a v-shaped body, which
women found more attractive during the fertile phase of their
menstrual cycle (see Little et al. 2007), and shaving body hair
makes these traits more visible. On the other hand, in contemporary Finland, body hair may be a signifier (positive or negative) of some target of learned prejudice: social class, ethnic
background, etc. For example, Finnish and other Scandinavians are on average much less hairy than immigrant men
from other parts of Europe and from Middle East. Thus, we
are not able rule out the possibility that there is interaction
between cultural predisposition and sexual receptivity.
We found that women’s preferences with regard to male
trunk hair increased with age. Although most of the younger
women favored shaved male bodies, most of the older women
preferred hairy ones. Postmenopausal women also had a stronger preference for hairiness than premenopausal ones, even
when the age differences between the groups were controlled,
suggesting that the menopause changes women’s preferences
in men. One might think it as a by-product of changes in fashion or changes in degree of cultural exposure to body hairs
over the lifetime, especially when women were actively seeking
mates, which might have affected women’s preferences later
in life. However, the finding that menstrual cycle, pregnancy,
and menopause have effect on women preference on body
hairs is a strong argument against the interpretation that
change in fashion would explain why older women preferred
more hairy men. Rather, it suggests that sex hormones might
have effect on preferences (see Welling et al. 2007). Thus,
it seems possible that the menopause changes women’s preferences in men due to change in sex hormones. Postmenopausal women are not fertile (Gilbert 2000), which is thought
to cause a shift in women away from a mating-oriented psychology toward a more kin- and community-oriented one
(Hawkes et al. 1998). If men with a hairy trunk apparently
have higher estradiol levels (see Winkler and Christiansen
1993), which are known to be associated with higher parental
care in males, it seems possible that after the menopause,
a woman’s preference may change toward better parental
and/or grandparental care.
Although previous studies have found that women evaluate
the figures of hairy men as being older than the ones of naked
men (Dixson et al. 2003), in this study, we did not find any
correlation between a male’s hairiness and his age. Among
Finnish men, hairiness apparently does not change much after puberty or early adolescence, and individual variation in
hairiness is greater than possible changes in hairiness after
puberty. Thus, our finding that older women found hair less
aversive than younger women might not be solely a result of
age-assortative mate preference.
Many interspecific cross-fostering experiments using birds,
mammals, and fish that give parental care suggest that during
pair formation, adults tend to prefer sexual partners of the species that gave them parental care when young rather than other
adults of their own species (Immelmann et al. 1991; ten Cate
et al. 2006). Likewise, studies using novel or artificially exaggerated ornaments have found sexual imprinting on these
ornaments (ten Cate and Bateson 1989). Interestingly, the
hairiness of a woman’s father correlated positively with her
preference with regard to body hair and the hairiness of her
current boyfriend/husband. This suggests either that women
are sexually imprinted for the hairiness of their father or that
women’s preference for body hair is heritable. Unfortunately,
these effects can be isolated only by using adoptive families.
These findings suggest that body hair may play a much more
important role in human mate choice than previously thought
and that biological factors, such as hormones and sexual imprinting or heritable preferences, may explain individual variation in women’s preferences with regard to body hair. Clearly,
more experimental studies are needed to show whether
changes in women’s preferences on body hairs with menstrual
cycle are widespread among different human cultures before
any generalization can be made. Furthermore, although it is
hard to distinguish between cultural and genetic effects, studies are needed which test whether women’s preferences for
body hair really do fluctuate across time and cultures, as has
been commonly thought, if we want to understand the rules
according to which we construct our ideals of human beauty.
Our study suggests that women’s preference on a trait that is
not an indicator of good genes and whose preference may be
culturally based changes with the cycle. It would be interesting
to know whether women’s preference on many other traits that
do not signal good genes, like men’s hair style or clothing,
changes with the cycle.
FUNDING
Academy of Finland to M.J.R.
We wish to thank Viola Elenius, Sari Haapaniemi, Laura Linko, Päivi
Kaulin, Kristian Mäkelä, Marja-Leena Pärkki, Minna Pölkki, and Terhi
Valtonen for their assistance in the field and in the laboratory. We also
thank Sue Aitken, Gil Rosenthal, Katariina Kangassalo, Anssi Susilahti,
and 2 anonymous referees for their very helpful comments on the
manuscript. Ellen Valle kindly checked the language.
REFERENCES
Basow SA. 1991. The hairless ideal: women and their body hair. Psychol Women Q. 15:83–96.
Basow SA, Braman AC. 1998. Women and body hair: social perception
and attitudes. Psychol Women Q. 222:637–645.
Berg SJ, Wynne-Edwards KE. 2001. Changes in testosterone, cortisol,
and estradiol levels in men becoming fathers. Mayo Clin Proc.
76:582–592.
Booth A, Dabbs J. 1993. Testosterone and men’s marriages. Soc
Forces. 72:463–477.
Rantala et al.
•
Body hair and sexual selection
Boroughs M, Cafri G, Thompson JK. 2005. Male body depilation:
prevalence and associated features of body hair removal. Sex Roles.
52:637–644.
Brown WM, Price ME, Kang J, Pound N, Zhao Y, Yu H. 2008. Fluctuating asymmetry and preferences for sex-typical bodily characteristics. Proc Natl Acad Sci USA. 105:12938–12943.
Burnham TC, Chapman JF, Gray PB, McIntyre MH, Lipson SF, Ellison
PT. 2003. Men in committed, romantic relationships have lower
testosterone. Horm Behav. 44:119–122.
Burton JL, Halim MM, Meyrick G, Jeans WD, Murphy D. 1979. Malepattern alopecia and masculinity. Br J Dermatol. 100:567–571.
ten Cate C, Bateson P. 1989. Sexual imprinting and a preference for
supernormal partners in Japanese quail. Anim Behav. 38:356–357.
ten Cate C, Verzijden MN, Etman E. 2006. Sexual imprinting can
induce sexual preferences for exaggerated parental traits. Curr
Biol. 16:1128–1132.
Collins SA. 2000. Men’s voices and women’s choices. Anim Behav.
60:773–780.
Darwin C. 1871. The descent of man, and selection in relation to sex.
London: John Murray.
Dixson AF, Halliwell G, East R, Wignarajah P, Anderson MJ. 2003.
Masculine somatotype and hirsuteness as determinants of sexual
attractiveness to women. Arch Sex Behav. 32:29–39.
Dixson BJ, Dixson AF, Li BG, Anderson MJ. 2007. Studies of human
physique and sexual attractiveness: sexual preferences of men and
women in China. Am J Hum Biol. 19:88–95.
Dixson BJ, Dixson AF, Morgan B, Anderson MJ. 2007. Human physique and sexual attractiveness: sexual preferences of men and
women in Bakossiland, Cameroon. Arch Sex Behav. 36:369–375.
Dunson DB, Baird DD, Wilcox AJ, Weinberg CR. 1999. Day-specific
probabilities of clinical pregnancy based on two studies with imperfect measures of ovulation. Hum Reprod. 14:1835–1839.
Fan J, Dai W, Liu F, Wu J. 2005. Visual perception of male body
attractiveness. Proc R Soc Lond B Biol Sci. 272:219–226.
Feinberg DR, Jones BC, Law-Smith MJ, Moore FR, DeBruine LM,
Cornwell RE, Hillier SG, Perrett DI. 2006. Menstrual cycle, trait
estrogen level, and masculinity preferences in the human voice.
Horm Behav. 49:215–222.
Folstad I, Karter AJ. 1992. Parasites, bright males and the immunocompetence handicap. Am Nat. 139:603–622.
Frost P. 1994. Preference for darker faces in photographs at different
phases of the menstrual cycle: preliminary assessment of evidence
for a hormonal relationship. Percept Mot Skills. 79:507–514.
Gangestad SW, Simpson JA, Cousins AJ, Garver-Apgar CE, Christensen
NP. 2004. Women’s preferences for male behavioral displays change
across the menstrual cycle. Psychol Sci. 15:203–207.
Gangestad SW, Thornhill R. 2008. Human oestrus. Proc R Soc Lond B
Biol Sci. 275:991–1000.
Gilbert SF. 2000. Developmental biology. Sunderland (MA): Sinauer.
Grammer K. 1993. 5-a-androst-16-en-3a-on: a male pheromone? A
brief report. Ethol Sociobiol. 14:201–207.
Havlicek J, Roberts SC, Flegr J. 2005. Women’s preference for dominant male odour: effects of menstrual cycle and relationship status.
Biol Lett. 1:256–259.
Hawkes K, O’Connell JF, Blurton Jones NG, Alvarez H, Charnov EL.
1998. Grandmothering, menopause, and the evolution of human
life histories. Proc Natl Acad Sci USA. 95:1336–1339.
Immelmann K, Prove R, Lassek R, Bischof HJ. 1991. Influence of adult
courtship experience on the development of sexual preferences in
zebra finch males. Anim Behav. 42:83–89.
Johnston VS, Hagel R, Franklin M, Fink B, Grammer K. 2001. Male
facial attractiveness: evidence for a hormone-mediated adaptive design. Evol Hum Behav. 22:251–267.
Jones BC, DeBruine LM, Perrett DI, Little AC, Feinberg DR, Law
Smith MJ. 2008. Effects of menstrual cycle phase on face preferences. Arch Sex Behav. 37:78–84.
423
Knussmann R, Christiansen K, Kannmacher J. 1992. Relations between sex hormone level and characters of hair and skin in healthy
young men. Am J Phys Anthropol. 88:59–67.
Kuukasjärvi S, Eriksson CJP, Koskela E, Nissinen K, Mappes T, Rantala MJ.
2004. Attractiveness of women body odours along menstrual
cycle: the role of oral contraceptives and receiver sex. Behav Ecol.
15:579–584.
Little AC, Jones BC, Burriss RP. 2007. Preferences for masculinity in
male bodies change across the menstrual cycle. Horm Behav. 31:
633–639.
Lookingbill DP, Demers LM, Wang C, Leung A, Rittmaster RS, Santen RJ.
1991. Clinical and biochemical parameters of androgen action in
normal healthy Caucasian versus Chinese subjects. J Clin Endocrinol
Metab. 72:1242–1248.
Lookingbill DP, Egan N, Santen RJ, Demers LM. 1988. Correlation of
serum 3 alpha-androstanediol glucuronide with acne and chest hair
density in men. J Clin Endocrinol Metab. 67:986–991.
Luciano L. 2001. Looking good: male body image in modern
America. New York: Hill and Wang.
Martins Y, Tiggemann M, Churchett L. 2008. Hair today, gone tomorrow: a comparison of body hair removal practices in gay and heterosexual men. Body Image. 5:312–316.
Pawlowski B, Jasienska G. 2005. Women’s preferences for sexual dimorphism in height depend on menstrual cycle phase and expected duration of relationship. Biol Psychol. 70:38–43.
Penton-Voak IS, Perrett DI. 2000. Female preference for male
faces changes cyclically—further evidence. Evol Hum Behav. 21:
39–48.
Penton-Voak IS, Perrett DI, Castles DL, Kobayashi T, Burt DM, Murray
LK, Minamisawa R. 1999. Menstrual cycle alters face preference.
Nature. 399:741–742.
Puts DA. 2005. Mating context and menstrual phase affect women’s
preferences for male voice pitch. Evol Hum Behav. 26:388–397.
Rantala MJ. 1999. Human nakedness: adaptation against ectoparasites? Int J Parasitol. 29:1987–1989.
Rantala MJ. 2007. The evolution of nakedness in Homo sapiens.
J Zool. 273:1–7.
Rantala MJ, Eriksson CJP, Vainikka A, Kortet R. 2006. Male steroid
hormones and female preference for male body odor. Evol Hum
Behav. 27:259–269.
Roberts SC, Gosling LM, Carter V, Petrie M. 2008. MHC correlated
odour preferences in humans and the use of oral contraceptives.
Proc R Soc Lond B Biol Sci. 275:2715–2722.
Roberts SC, Havlicek J, Flegr J, Hruskova M, Little AC, Jones BC,
Perrett DI, Petrie M. 2004. Female facial attractiveness increases
during the fertile phase of the menstrual cycle. Proc R Soc Lond
B Biol Sci. 271:S270–S272.
Tiggemann M, Hodgson S. 2008. The hairlessness norm extended.
Sex Roles. 59:889–897.
Tiggemann M, Kenyon SJ. 1998. The hairiness norm: the removal of
body hair in women. Sex Roles. 39:873–885.
Toerien M, Wilkinson S. 2003. Gender and body hair: constructing the
feminine woman. Womens Stud Int Forum. 26:333–344.
Trainor CB, Marler CA. 2002. Testosterone promotes paternal behavior in a monogamous mammal via conversion to oestrogen. Proc R
Soc Lond B Biol Sci. 269:823–829.
Welling LLM, Jones BC, DeBruine LM, Conway CA, Law Smith MJ,
Little AC, Feinberg DR, Sharp M, Al-Dujaili EAS. 2007. Raised salivary testosterone in women is associated with increased attraction
to masculine faces. Horm Behav. 52:156–161.
Wilcox AJ, Dunson D, Baird DD. 2000. The timing of the ‘‘fertile
window’’ in the menstrual cycle: day specific estimates from a prospective study. BMJ. 321:1259–1262.
Winkler E-M, Christiansen K. 1993. Sex hormone levels and body hair
growth in !Kung San and Kavango men from Namibia. Am J Phys
Anthropol. 92:155–164.