Showing posts with label Masculinity. Show all posts
Showing posts with label Masculinity. Show all posts

June 04, 2012

Broad-faced men more co-operative in inter-group conflict

rom the press release:
The researchers gave University of St Andrews students money to play a game in groups where they could either benefit themselves and free-ride on the cooperation of others or they could risk their money to benefit their group. Half of the students were told that the outcomes of the game would be compared between St Andrews students, the other half that they would be compared with a rival university. The prediction was that the wider faced men would respond to the rivalry in the second condition and sacrifice their money for their own group.

The results of the study confirmed their hypotheses and turned the typical associations with facial width on their head: the more robust looking, wider faced men in the study were more self-sacrificing than other men.

"It was surprising that our predictions were confirmed," reports Dr. Stirrat. "When we mentioned Edinburgh University, our St Andrews participants with wider faces were more cooperative than the other men. When we didn't mention the rivalry, they were less cooperative than other men."
Related links between wide faces and aggression, trustworthiness, company performance and unethical behavior.

Psychological Science doi: 10.1177/0956797611435133

Face Structure Predicts Cooperation Men With Wider Faces Are More Generous to Their In-Group When Out-Group Competition Is Salient

M. Stirrat and D. I. Perrett

Male facial width-to-height ratio appears to correlate with antisocial tendencies, such as aggression, exploitation, cheating, and deception. We present evidence that male facial width-to-height ratio is also associated with a stereotypically male prosocial tendency: to increase cooperation with other in-group members during intergroup competition. We found that men who had wider faces, compared with men who had narrower faces, showed more self-sacrificing cooperation to help their group members when there was competition with another group. We propose that this finding makes sense given the evolutionary functions of social helpfulness and aggression.

Link

November 13, 2010

Skin yellowness but not masculinity as indicators of male facial attractiveness


We should keep in mind that this sample was recruited from a fairly homogeneous population, and thus is not directly relevant if one is interested in attractiveness of people of different ancestry.

From the paper:
The regression retained only skin yellowness as a predictor of attractiveness, and the effect of skin yellowness was positive and highly significant (F(1,71) = 10.806, Beta = .366, t = 3.287, p less than .002). Skin lightness, redness and morphological masculinity did not significantly predict attractiveness (all p>.114, see Table 1).


On the left, faces that scored low/high in brightness (top), redness (middle), and yellowness (bottom). On the right, composites of low/high masculinity based on morphology (top row), ratings (middle row), and morphing of faces in a more feminine (bottom left) or more masculine direction (bottom right).
PLoS One. 2010 Oct 27;5(10):e13585.

Does masculinity matter? The contribution of masculine face shape to male attractiveness in humans.

Scott IM, Pound N, Stephen ID, Clark AP, Penton-Voak IS.

Abstract

BACKGROUND: In many animals, exaggerated sex-typical male traits are preferred by females, and may be a signal of both past and current disease resistance. The proposal that the same is true in humans - i.e., that masculine men are immunocompetent and attractive - underpins a large literature on facial masculinity preferences. Recently, theoretical models have suggested that current condition may be a better index of mate value than past immunocompetence. This is particularly likely in populations where pathogenic fluctuation is fast relative to host life history. As life history is slow in humans, there is reason to expect that, among humans, condition-dependent traits might contribute more to attractiveness than relatively stable traits such as masculinity. To date, however, there has been little rigorous assessment of whether, in the presence of variation in other cues, masculinity predicts attractiveness or not.

METHODOLOGY/PRINCIPAL FINDINGS: The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour - a fluctuating, condition-dependent cue - was a significant predictor of attractiveness.

CONCLUSIONS/SIGNIFICANCE: These findings suggest that facial morphological masculinity may contribute less to men's attractiveness than previously assumed. Our results are consistent with the hypothesis that current condition is more relevant to male mate value than past disease resistance, and hence that temporally fluctuating traits (such as colour) contribute more to male attractiveness than stable cues of sexual dimorphism.

Link

November 02, 2008

Sexy parents produce sexy daughters (but not sons)

A very interesting new paper in Animal Behaviour regarding the inheritance of masculinity/famininity and attractiveness. On the left are composites of 10 attractive parents and their daughters, and on the right composites of 10 unattractive parents and their daughters.

Not surprisingly, the attractive female looks similar to another facial composite in a recent study on facial correlates of sociosexuality by authors from the same institution (University of St. Andrews in the UK).

The difference between Fisherian runaway selection and "good genes" theory -mentioned below- is that in the former, a "sexy" trait is selected even though it has no adaptive value (such as the peacock's tail), while in the latter the latter the "sexy" trait is that which signifies good genetic qualities (e.g. health).

From the paper:
Our findings are supportive of both Fisherian processes and good genes theory. Both parents contributed to the attractiveness and femininity of daughters. We found that daughter's attractiveness was predicted independently by father's attractiveness and mother's femininity (and therefore, by default, mother's attractiveness). Fisherian selection processes would suggest that men have evolved preferences for sexually dimorphic facial characteristics in opposite-sex partners, and through human evolution these preferences have increased the frequency of feminine facial characteristics such as a slender chin, full lips and large eyes in women. Good genes theory predicts the same finding, although it suggests that feminine facial characteristics must by definition signal good quality, including possible cues to immunocompetence, fertility, youthfulness, health and perhaps even maternal tendencies

...

We are perplexed as to why we did not find any evidence for the inheritance of attractiveness in males, through either the female or male parent. Attractiveness, by its own definition, should be sexy, and while we found evidence for sexy parents–sexy daughters, we did not find the parallel in male offspring. While masculine dads produced masculine sons, in this study, sexy parents did not produce sexy sons.
UPDATE : For a possible solution to this paradox, see next post.

Animal Behaviour doi: 10.1016/j.anbehav.2008.07.031

Sexy sons and sexy daughters: the influence of parents' facial characteristics on offspring

R. Elisabeth Cornwell, and David I. Perrett

Abstract

Choosing a mate to maximize fitness underlies all sexual selection theories. Key to understanding mate choice is the inheritance of particular traits. Using family photos, we evaluated the predictions made by sexual selection theories for human mate choice concerning the inheritance of facial characteristics and assortment in facial appearance of parents. We found that both fathers' and mothers' attractiveness predicted the facial attractiveness of daughters: ‘sexy daughters’. Fathers and sons were related to each other in facial masculinity but not attractiveness, providing only partial evidence for ‘sexy sons’. Mothers and sons did not relate in masculinity–femininity; neither did fathers and daughters. Parents were similar in attractiveness but masculine men were not partnered to feminine women. Our findings support some predictions of Fisherian selection processes and ‘good genes’ theory but are less consistent with ‘correlated response theory’ and the immunocompetence handicap principle.

Link

September 23, 2008

Facial masculinity and testosterone levels correlated (after a win)

Proceedings of the Royal Society B doi: 10.1098/rspb.2008.0990

Testosterone responses to competition in men are related to facial masculinity

Nicholas Pound et al.

Abstract

Relationships between androgens and the size of sexually dimorphic male traits have been demonstrated in several non-human species. It is often assumed that a similar relationship exists for human male faces, but clear evidence of an association between circulating testosterone levels and the size of masculine facial traits in adulthood is absent. Here we demonstrate that, after experimentally determined success in a competitive task, men with more a masculine facial structure show higher levels of circulating testosterone than men with less masculine faces. In participants randomly allocated to a ‘winning’ condition, testosterone was elevated relative to pre-task levels at 5 and 20min post-task. In a control group of participants allocated to a ‘losing’ condition there were no significant differences between pre- and post-task testosterone. An index of facial masculinity based on the measurement of sexually dimorphic facial traits was not associated with pre-task (baseline) testosterone levels, but was associated with testosterone levels 5 and 20min after success in the competitive task. These findings indicate that a man's facial structure may afford important information about the functioning of his endocrine system.

Link

September 08, 2008

Masculine vs. Feminine Walk

Walk this way? Masculine motion seems to come at you, while females walk away
You can tell a lot about people from the way they move alone: their gender, age, and even their mood, earlier studies have shown. Now, researchers reporting in the September 9th issue of Current Biology, a Cell Press publication, have found that observers perceive masculine motion as coming toward them, while a characteristically feminine walk looks like it's headed the other way.

Such studies are done by illuminating only the joints of model walkers and asking observers to identify various characteristics about the largely ambiguous figures.

"It's a really interesting thing," said Rick van der Zwan of Southern Cross University in Australia. "If you look at someone with just their joints illuminated when they aren't moving, it's difficult to tell what it is you are looking at. But as soon as they move, instantaneously, you can tell that it's a person and perceive their nature. You can tell if it's a boy or a girl, young or old, angry or happy.… You can discern all these qualities about their state, affect, and actions with no cues at all about what they look like—with no form at all, just motion."

Many previous studies of biological motion perception have relied on male figures as models, van der Zwan said. One of those earlier studies had noticed an interesting phenomenon: even though you can't really tell whether a so-called point-light figure is facing toward you or away, people seemed to perceive those figures always as facing in their direction.

Now, van der Zwan and his colleagues show that this isn't always true.

In their study, they allowed people to observe point-light figures representing a continuum from an extremely "girly girl" to a "hulking male." At the halfway point in between was a gender-neutral walker that observers judged as male half the time and female half the time.

Their results showed that walking male figures did indeed appear to face toward you. Female figures, on the other hand, seemed as though they faced away. The results are the first to show a link between the perception of gender from biological motion cues and the perception of orientation.

That same pattern emerged regardless of the gender of the person watching, a finding that van der Zwan considers an important clue about the behavior.

"Our data suggest that biological motion is an important cue for social organisms trying to operate in environments where other cues as to the actions or intentions of other organisms may be ambiguous," the researchers wrote. "Whilst the precise role of local cues in mediating these effects requires further explication, it is tempting to speculate that the orientation biases reported here reflect the development of perceptual mechanisms that weigh in the probable cost of misinterpreting the actions and intentions of others. For example, a male figure that is otherwise ambiguous might best be perceived as approaching to allow the observer to prepare to flee or fight. Similarly, for observers, and especially infants, the departure of females might signal also a need to act, but for different reasons."

I wonder what these different reasons are. A hint from our closest relatives:
Although chimpanzees virtually never adopt face-to-face positions, bonobos do so in one out of three copulations in the wild.
The "infant" explanation probably relates to a tendency to cry when a mother is perceived as leaving.

It will be interesting to see if ethnicity/race/social class can also be perceived by walking style. 

See also Walking speed in different cities.

Current Biology doi:10.1016/j.cub.2008.06.054

Correlated changes in perceptions of the gender and orientation of ambiguous biological motion figures

Anna Brooks et al.

The sensitivity of the mammalian visual system to biological motion cues has been shown to be general and acute [1], [2] and [3]. Human observers, in particular, can deduce higher-order information, such as the orientation of a figure (which way it is facing), its gender, emotional state, and even personality traits, on the basis only of sparse motion cues. Even when the stimulus information is confined to point lights attached to the major joints of an actor (so-called point-light figures), observers can use information about the way the actor is moving to tell what they are doing, whether they are a male or female, and how they are feeling [4], [5] and [6]. Here we report the novel finding that stimulus manipulations that made such walkers appear more female also had the effect of making the walkers appear more often as if they were walking away from rather than towards observers. Using frontal-view (or rear-view) point-light displays of human walkers, we asked observers to judge whether they seemed to be walking towards or away from the viewing position. Independent of their own gender, observers reliably reported those figures they perceived to be male as looking like they were approaching (as reported in [7]), but those they perceived to be female as walking away. Furthermore, figures perceived to be gender-neutral also appeared more often, although not exclusively, to be walking towards observers.

Link

Balancing selection and homosexuality

The idea in this paper is that the genetic factors leading one to be homosexual also lead one to have higher mating success if he turns out to be heterosexual.

The use of "lifetime number of opposite sex sexual partners" as a stand-in for reproductive success is fairly problematic. It seems more likely that a couple that marries young with limited pre-marital experience will have a higher number of children than individuals who spend a lot of time having sex with multiple people (not to mention the risk to one's health from such behavior).

In my own opinion (see Beautiful Wives and Gay Sons) homosexuality is rooted in a side-effect of the expression of femininity-- or masculinity-enhancing traits in individuals of the wrong gender: if, e.g., a couple has an excess of "feminine" DNA between them, it may produce reproductively successful daughters but sons at higher risk for homosexuality. These genes are more successful (than average) in female bodies, and less than average in male ones: thus they are maintained in the gene pool.

There is a good case to be made, however, for a link between homosexuality and promiscuity. A certain lack of inhibition may be linked to the expression of the homosexual phenotype; this may explain why homosexuals tend to have more partners than average compared to heterosexuals. 

Evolution and Human Behavior doi: 10.1016/j.evolhumbehav.2008.07.002

Genetic factors predisposing to homosexuality may increase mating success in heterosexuals

Brendan P. Zietsch et al.

Abstract

There is considerable evidence that human sexual orientation is genetically influenced, so it is not known how homosexuality, which tends to lower reproductive success, is maintained in the population at a relatively high frequency. One hypothesis proposes that while genes predisposing to homosexuality reduce homosexuals' reproductive success, they may confer some advantage in heterosexuals who carry them. However, it is not clear what such an advantage may be. To investigate this, we examine a data set where a large community-based twin sample (N=4904) anonymously completed a detailed questionnaire examining sexual behaviors and attitudes. We show that psychologically masculine females and feminine men are (a) more likely to be nonheterosexual but (b), when heterosexual, have more opposite-sex sexual partners. With statistical modelling of the twin data, we show that both these relationships are partly due to pleiotropic genetic influences common to each trait. We also find a trend for heterosexuals with a nonheterosexual twin to have more opposite-sex partners than do heterosexual twin pairs. Taken together, these results suggest that genes predisposing to homosexuality may confer a mating advantage in heterosexuals, which could help explain the evolution and maintenance of homosexuality in the population.

Link

April 07, 2008

How tall you are may predict how jealous you are

Evolution and Human Behavior
Volume 29, Issue 2, March 2008, Pages 133-139

Height predicts jealousy differently for men and women

Abraham P. Buunk et al.

Abstract

Because male height is associated with attractiveness, dominance, and reproductive success, taller men may be less jealous. And because female height has a curvilinear relationship with health and reproductive success (with average-height females having the advantages), female height may have a curvilinear relationship with jealousy. In Study 1, male height was found to be negatively correlated with self-reported global jealousy, whereas female height was curvilinearly related to jealousy, with average-height women reporting the lowest levels of jealousy. In Study 2, male height was found to be negatively correlated with jealousy in response to socially influential, physically dominant, and physically attractive rivals. Female height was negatively correlated with jealousy in response to physically attractive, physically dominant, and high-social-status rivals; in addition, quadratic effects revealed that approximately average-height women tend to be less jealous of physically attractive rivals but more jealous of rivals with “masculine” characteristics of physical dominance and social status.

Link

January 05, 2007

Facial masculinity

From LiveScience:
In the study, 854 male and female subjects viewed a series of male head shots that had been digitally altered to exaggerate or minimize masculine traits. The participants then answered questions about how they expected the men in the photos to behave.

Overwhelmingly, participants said those with more masculine features were likely to be risky and competitive and also more apt to fight, challenge bosses, cheat on spouses and put less effort into parenting. Those with more feminine faces were seen as good parents and husbands, hard workers and emotionally supportive mates [compare examples].

Despite all the negative attributes, when asked who they would choose for a short-term relationship, women still selected the more masculine looking men. Brad and George then would be picks for a brief romance, if not the long haul.


Personal Relationships
Volume 13 Issue 4 Page 451 - December 2006

Male facial masculinity influences attributions of personality and reproductive strategy

DANIEL J. KRUGER

Abstract

Facial masculinity may be used as a cue in female mate choice, as it reflects the success of the male genotype in its developmental environment. Women may maximize reproductive success by using a conditional strategy favoring highly masculine facial features for short-term relationships and feminized facial features in men for long-term relationships. Three studies examine reactions to masculinized and feminized male facial composites. Properties of the original composite image affect ratings of critical attributes and the magnitude of the differences in ratings between versions undergoing identical processes of geometric manipulation (Study 1). Both men and women attribute personality, behavior, and mating strategies consistent with predictions derived from the good genes and mating trade-off hypotheses (Study 2). Participants accurately grouped behavioral tendencies related to high mating effort/risky strategies and high parenting effort/risk adverse strategies and associated mating effort more so with masculinized faces and parenting effort more so with feminized faces (Study 3). These results indicate that male facial masculinity serves as a visual cue for inferring personality and reproductive strategy.

Link

December 13, 2006

Sexual preferences in China

Am J Hum Biol. 2006 Dec 7;19(1):88-95 [Epub ahead of print]

Studies of human physique and sexual attractiveness: Sexual preferences of men and women in China.

Dixson BJ, Dixson AF, Li B, Anderson MJ.

Men and women at Northwest University (n = 631), Xi'an, China, were asked to rate the attractiveness of male or female figures manipulated to vary somatotype, waist-to-hip ratio (WHR), secondary sexual traits, and other features. In study 1, women rated the average masculine somatotype as most attractive, followed by the mesomorphic (muscular), ectomorphic (slim), and endomorphic (heavily built) somatotypes, in descending order of preference. In study 2, the amount and distribution of masculine trunk (chest and abdominal) hair were altered progressively in a series of front-posed figures. Women rated figures with no or little trunk hair as most attractive. Study 3 assessed the attractiveness of front-posed male figures which varied only in length of their nonerect penis. Numerical ratings for this trait were low, but moderate lengthening of the penis (22% or 33% above average) resulted in a significant increase in scores for attractiveness. In study 4, Chinese men rated the attractiveness of back-posed female images varying in waist-to-hip ratio (WHR from 0.5-1.0). The 0.6 WHR figure was most preferred, followed by 0.7, while figures with higher ratios (0.9 or 1.0) were significantly less attractive. Study 5 rated the attractiveness of female skin color: men expressed a marked preference for images which were lighter in color, as compared to images of average or darker skin colors. These results, the first of their kind reported for a Chinese population, support the view that sexual selection has influenced the evolution of human physique and sexual attractiveness in men and women.

Link

Physical strength in men correlates with attractiveness

Am J Hum Biol. 2006 Dec 7;19(1):82-87 [Epub ahead of print]

Male facial appearance signals physical strength to women.

Fink B, Neave N, Seydel H.

Previous studies showed that male faces with extreme features that are likely to be associated with testosterone (T) are perceived as dominant and masculine. Women were reported to prefer masculinized male faces, as they may consider T markers to be an "honest" indication of good health. However, it is also likely that female preferences for certain male faces arise from the fact that dominant- and masculine-looking males are signaling characteristics which may be beneficial in intrasexual conflict, and thereby also indicate potential achievers of high status, an important factor in female mate selection. Although numerous studies were built on this assumption, nothing is known about the relationship between perceived facial dominance and physical strength in men. We measured hand-grip strength, as a measure of overall physical strength, in a sample of 32 male students, and recorded age, body weight, and height. Seventy-nine women rated facial images of these men for dominance, masculinity, and attractiveness. After controlling for age and body weight, hand-grip strength was found to correlate significantly positively with all three measures. The present data thus support the supposition that a male's physical strength is also signaled via facial characteristics of dominance and masculinity, which are considered attractive by women

Link

December 01, 2006

Sexual preferences for human physique in Cameroon

Arch Sex Behav. 2006 Nov 30; [Epub ahead of print]

Human Physique and Sexual Attractiveness: Sexual Preferences of Men and Women in Bakossiland, Cameroon.

Dixson BJ, Dixson AF, Morgan B, Anderson MJ.

Men and women living in a rural community in Bakossiland, Cameroon were asked to rate the attractiveness of images of male or female figures manipulated to vary in somatotype, waist-to-hip ratio (WHR), secondary sexual traits, and other features. In Study 1, women rated mesomorphic (muscular) and average male somatotypes as most attractive, followed by ectomorphic (slim) and endomorphic (heavily built) figures. In Study 2, amount and distribution of masculine trunk (chest and abdominal) hair was altered progressively in a series of front-posed male figures. A significant preference for one of these images was found, but the most hirsute figure was not judged as most attractive. Study 3 assessed attractiveness of front-posed male figures which varied only in length of the non-erect penis. Extremes of penile size (smallest and largest of five images) were rated as significantly less attractive than three intermediate sizes. In Study 4, Bakossi men rated the attractiveness of back-posed female images varying in WHR (from 0.5-1.0). The 0.8 WHR figure was rated markedly more attractive than others. Study 5 rated the attractiveness of female skin color. Men expressed no consistent preference for either lighter or darker female figures. These results are the first of their kind reported for a Central African community and provide a useful cross-cultural perspective to published accounts on sexual selection, human morphology and attractiveness in the U.S., Europe, and elsewhere.

Link

April 27, 2006

Femininity/Masculinity predicts male but not female homosexuality

A new article illustrates that masculinity-feminity of adolescents predicts sexual orientation in adulthood for males, but not for females. In other words, effeminate adolescents tend to grow up to be gay but this is not the case for more masculine women.

This illustrates that male and female homosexuality are different phenomena, something which is also apparent by (a) the greater prevalence of male compared to female homosexuality, and (b) the much more obvious behavioral cues of male compared to female homosexuals.

As I wrote in the old Dodona forum in 2004, distinguishing between male and female homosexuality:
Some boys are naturally effeminate or girly and are more prone to develop an abnormal sexuality during their childhood. Homosexuality is a mental illness but one which is difficult to treat because it starts early on and becomes a part of a person's core personality by the time he becomes an adult. While most men learn to act like men as part of the growin up process, homosexuals must unlearn their whole development and relearn a sexual role, something which is virtually impossible.

For lesbians, the cause is probably ugliness or fear of men. While male homosexuals often have a 'normal' appearance, lesbians tend to be unattractive -- except in porn movies of course.
Journal of Biosocial Science (forthcoming)

MASCULINITY–FEMININITY PREDICTS SEXUAL ORIENTATION IN MEN BUT NOT IN WOMEN

J. RICHARD UDRY a1 and KIM CHANTALA

Abstract

Using the nationally representative sample of about 15,000 Add Health respondents in Wave III, the hypothesis is tested that masculinity–femininity in adolescence is correlated with sexual orientation 5 years later and 6 years later: that is, that for adolescent males in 1995 and again in 1996, more feminine males have a higher probability of self-identifying as homosexuals in 2001–02. It is predicted that for adolescent females in 1995 and 1996, more masculine females have a higher probability of self-identifying as homosexuals in 2001–02. Masculinity–femininity is measured by the classical method used by Terman & Miles. For both time periods, the hypothesis was strongly confirmed for males: the more feminine males had several times the probability of being attracted to same-sex partners, several times the probability of having same-sex partners, and several times the probability of self-identifying as homosexuals, compared with more masculine males. For females, no relationship was found at either time period between masculinity and sex of preference. The biological mechanism underlying homosexuality may be different for males and females.

Link

February 01, 2006

The pitch of male voices

Evolution and Human Behavior (Article in Press)

Dominance and the evolution of sexual dimorphism in human voice pitch

David Andrew Puts et al.

Abstract

The developmental and anatomical causes of human voice sexual dimorphisms are known, but the evolutionary causes are not. Some evidence suggests a role of intersexual selection via female mate choice, but other evidence implicates male dominance competition. In this study, we examine the relationships among voice pitch, dominance, and male mating success. Males were audio recorded while participating in an unscripted dating-game scenario. Recordings were subsequently manipulated in voice pitch using computer software and then rated by groups of males for dominance. Results indicate that (1) a masculine, low-pitch voice increases ratings of men's physical and social dominance, augmenting the former more than the latter; and (2) men who believe they are physically dominant to their competitor lower their voice pitch when addressing him, whereas men who believe they are less dominant raise it. We also found a nonsignificant trend for men who speak at a lower pitch to report more sexual partners in the past year. These results are consistent with the hypothesis that male intrasexual competition was a salient selection pressure on the voices of ancestral males and contributed to human voice sexual dimorphism.

Link

April 23, 2005

Attractiveness and sexual activity

Evolution and Human Behavior Volume 26, Issue 2 , March 2005, Pages 186-201

Attractiveness and sexual behavior: Does attractiveness enhance mating success?

Gillian Rhodes et al.

Abstract

If attractiveness is an important cue for mate choice, as proposed by evolutionary psychologists, then attractive individuals should have greater mating success than their peers. We tested this hypothesis in a large sample of adults. Facial attractiveness correlated with the number of short-term, but not long-term, sexual partners, for males, and with the number of long-term, but not short-term, sexual partners and age of first sex, for females. Body attractiveness also correlated significantly with the number of short-term, but not long-term, sexual partners, for males, and attractive males became sexually active earlier than their peers. Body attractiveness did not correlate with any sexual behavior variable for females. To determine which aspects of attractiveness were important, we examined associations between sexual behaviors and three components of attractiveness: sexual dimorphism, averageness, and symmetry. Sexual dimorphism showed the clearest associations with sexual behaviors. Masculine males (bodies, similar trend for faces) had more short-term sexual partners, and feminine females (faces) had more long-term sexual partners than their peers. Feminine females (faces) also became sexually active earlier than their peers. Average males (faces and bodies) had more short-term sexual partners and more extra-pair copulations (EPC) than their peers. Symmetric women (faces) became sexually active earlier than their peers. Given that male reproductive success depends more on short-term mating opportunities than does female reproductive success, these findings suggest that individuals of high phenotypic quality have higher mating success than their lower quality counterparts.

Link

October 08, 2004

Are women getting more feminine?

A reader of iSteve writes that perhaps women are getting more feminine:

I suspect the traits that make being a mother attractive are "feminine", such as taking pleasure in nurturing others. An ambitious woman with a aggressive personality is likely to choose to be a newspaper reporter (explaining partially why the writers or so feminist), but this choice is likely to go along with having fewer children. (Alas, high IQ makes a interesting career easier to achieve and leads to fewer offspring). Thus, I suspect there is already strong selection for femininity.

An interesting suggestion, but an argument can be made in favor of women becoming less "feminine". If a person's femininity or masculinity depends on how feminine/masculine their parents are, then in today's age many "feminine" men are choosing the homosexual lifestyle [1] instead of choosing to lead a "regular" family life. This probably shifts the genetic balance in favor of "masculine" traits, in addition to the common observation that often girls might pick up more "male-like' traits due to being raised in a house by a "masculine" father who does man-like activities [2]

A second argument is that success in the workplace in many cases depends on being attractive. Attractive, feminine women get more career breaks, hence they may be more likely to have decreased fitness. Not to mention that attractive people are often more intelligent, as both intelligence and attractiveness are partially depended on health which in turn depends on genetic factors.

[1] Lesbians on the other hand are (i) fewer than male homosexuals, and (ii) have a much easier option of having kids if they choose to. Hence increased lesbianism and increased male homosexuality do not balance each other out.
[2] This would affect the frequency of feminine phenotypes but would probably be counterbalanced by improved cosmetic technologies which are leading to a more efficient phenotypic feminization of women.