2009 June 29 Monday
Men In Closer Agreement Than Women On Attractiveness

Guys know what they want and they pretty much agree with each other on who is hot.

There is much more consensus among men about whom they find attractive than there is among women, according to a new study by Wake Forest University psychologist Dustin Wood.

The study, co-authored by Claudia Brumbaugh of Queens College, appears in the June issue of the Journal of Personality and Social Psychology.

"Men agree a lot more about who they find attractive and unattractive than women agree about who they find attractive and unattractive," says Wood, assistant professor of psychology. "This study shows we can quantify the extent to which men agree about which women are attractive and vice versa."

Unfortunately the press release does not provide any quantitative results. Here is the abstract which also doesn't provide much details. You can buy the article at that link.

The pictures of men and women were only between the ages 18 and 25. I would like to see a study using a wider age range. My expectation is that female attractiveness will be seen as dropping off with age a lot faster than male attractiveness. Also, I'd like to see a study that uses psychometrics to compare attractiveness of women and men based on both the IQ of the viewer and the viewee. Do smart people find smart people more attractive? Do dumb people find smart or dumb people more attractive? Also, I'd like to know how the physical traits and character traits of men and women affect what they see as attractive. For example, does a guy with more masculine physical features and dominant personality feel greater attraction to the most feminine-looking women or to less feminine-looking women?

More than 4,000 participants in the study rated photographs of men and women (ages 18-25) for attractiveness on a 10-point scale ranging from "not at all" to "very." In exchange for their participation, raters were told what characteristics they found attractive compared with the average person. The raters ranged in age from 18 to more than 70.

Before the participants judged the photographs for attractiveness, the members of the research team rated the images for how seductive, confident, thin, sensitive, stylish, curvaceous (women), muscular (men), traditional, masculine/feminine, classy, well-groomed, or upbeat the people looked.

Breaking out these factors helped the researchers figure out what common characteristics appealed most to women and men.

Men's judgments of women's attractiveness were based primarily around physical features and they rated highly those who looked thin and seductive. Most of the men in the study also rated photographs of women who looked confident as more attractive.

As a group, the women rating men showed some preference for thin, muscular subjects, but disagreed on how attractive many men in the study were. Some women gave high attractiveness ratings to the men other women said were not attractive at all.

The press release doesn't indicate whether the pictures were full body or just face. Do ratings of just faces predict ratings of full bodies? I'd expect fat distribution to have a big impact on that. A buxom woman will pick up points in a full body shot while a pot belly will decrease attraction.

So why are men more consistent in their judgments? Do women differ from each other more than men do in their mating strategies? Or is the study picking up on greater variation over time in terms of what women want in men? In particular, how much of the female difference was due to the women being at different stages of their menstrual cycles? See my post Ovulating Women Prefer Smell Of Dominant Men and also my post Nursing Women More Attracted To Higher Pitch Male Voices. Monthly hormonal variations are going to cause women to feel more attraction to alpha men with more masculine features when the women are ovulating and then toward beta men to help raise the kids.

Another possible cause of the greater female difference might be due to age of the females. Does a 35 year old woman on average want different physical features (perhaps less masculinity) than a 20 year old woman? Maybe the full article gets into this. If anyone reads it post in the comments.

Update: Following up on comments made by bbartlog and David Friedman: If the pictures of men showed clearer signs of status (e.g. wearing a medical uniform with an MD on the name tag versus clothing for a lumberjack) would the female choices line up more closely? Or maybe in the pictures used some of the pictures showed status indicators which only some of the women noticed? How consistent are women in their status rankings?

By Randall Parker    2009 June 29 10:18 AM   Entry Permalink | Comments (15)
2006 December 14 Thursday
People Judge Male Personalities By Faces

More masculine-looking faces are judged to have greater tendencies to fight, sleep around, and otherwise act more like guys.

In one study, participants linked more masculinized faces with riskier and more competitive behaviors, higher mating effort and lower parenting effort in comparison with less masculine faces.

Men with highly masculine faces were judged more likely to get into physical fights, challenge their bosses, sleep with many women, cheat on their partners and knowingly hit on someone else's girlfriend. Those with more feminine faces were judged to be more likely to be good husbands, be great with children, work hard at their jobs even though they didn't like them, and be emotionally supportive in long-term relationships.

"Men picked the less masculine-looking men to accompany their girlfriends on a weekend trip to another city," Kruger said, "and both men and women would prefer the less masculine versions as dating partners for their daughters."

Together, the studies show that highly masculine faces are associated with riskier and more competitive behavior, higher mating effort and lower parenting effort in comparison with less masculine faces.

"Both men and women generally respond to men with high and low facial masculinity in ways that could be expected to benefit their own reproductive success," Kruger said. "While the more masculine-looking men may be good bets for mating, the more feminine-looking men may be better bets as parenting partners. More feminine features suggest compassion and kindness, indicating that men are able and willing to invest in a long-term relationship and in any potential children."

But will a masculine appearance help or hurt your career? It is hard to separate out the effect of the appearance and the effect of the behavioral tendencies that correlate with that appearance.

Humans are going to become more confused with each other in the future because we will gain greater capabilities to change both our appearances and our personalities. A guy will be able to make himself look more feminine-looking while he has his mind molded to make him more masculine in behavior. Might there be an appeal for this strategy since it would allow a person to be underestimated? Would people let their guards down around a more feminine looking guy?

What I want to know: When offspring genetic engineering becomes possible will people make their sons and daughters more feminine or more masculine? Will the sexes become more alike or more different?

By Randall Parker    2006 December 14 10:23 PM   Entry Permalink | Comments (6)
2005 January 03 Monday
Do Men Want Dumber Women As Mates Or Are Smart Women Too Choosy?

Social scientists at the universities of Aberdeen, Bristol, Edinburgh and Glasgow in Britain tested the IQs of 900 boys and girls at the age of 11 and then checked on their rates of marriage 40 years later. They found that higher IQ increases the chances a man will marry but high IQ causes an even greater decrease in the chances that a woman will marry. (same article here)

“The finding that IQ in early life appears to be associated with the likelihood to marry is important because factors in childhood may determine a person’s marital status in adulthood, which may in turn influence future health and mortality,” says the study, to appear in the Journal of Personality and Individual Differences.

For boys, there is a 35% increase in the likelihood of marriage for each 16-point rise in IQ. For girls, there is a 40% drop for each 16-point increase.

One possible cause of this result is that many smarter women find it beneath them to be wives. Or perhaps they are too choosy in wanting higher status men whereas the men are not as choosy about status of females and hence can find a suitable mate from a much larger pool of women. Men are more driven to seek physical beauty and youth as a result of selective pressures to seek fertile mates. Whereas natural selection favored a female preference for higher status men as better providers.

For the lower status and less intelligent women the smart successful men (and smart men are more successful on average) look like great catches that allow the women to move up in status and in creature comforts. They might also see smarter men as likely to treat them more thoughtfully (at least on average - though there are smart and callous men of course).

Another possible cause in the reduction in marriage rates for higher IQ women is that they spend more time in school than lower IQ women and therefore delay marriage past the point of their maximum attractiveness and maximum fertility. This is certainly consistent with a study on the Australian Twins Registry found that higher education reduces reproductive fitness of women. It would be interesting to look at the women in the most recent study to see if higher IQ still lowered marriage rates once educational attainment was adjusted for.

Go back and read the comments of my previous post Men Prefer Subordinate Women For Long Term Relationships. Note that some people really took issue when I advanced the argument that smarter women are at a disadvantage in finding a mate. Here is social science data that really proves the common intuition. Anyone still want to dispute this argument?

Here is what I want to know: Are genes for higher IQ being selected against? If smarter men are marrying more are they having more kids to compensate for the fact that smarter women are having fewer kids? My guess is that there is a net dysgenic effect. However, in America there is one higher IQ group that has a higher fertility rate: Higher income Republicans have more children than lower income Republicans and various groups of Democrats. So the selective pressures on genes for IQ are hard to tease out. We need cheap DNA sequencing which will probably come along in 5 to 10 years and settle this question.

By Randall Parker    2005 January 03 02:18 PM   Entry Permalink | Comments (102)
2004 December 13 Monday
Men Prefer Subordinate Women For Long Term Relationships

Men are more attracted to lower status females than to higher status females.

"These findings provide empirical support for the widespread belief that powerful women are at a disadvantage in the marriage market because men may prefer to marry less accomplished women," said Stephanie Brown, lead author of the study and a social psychologist at the U-M Institute for Social Research (ISR).

For the study, supported in part by a grant from the National Institute of Mental Health, Brown and co-author Brian Lewis from UCLA tested 120 male and 208 female undergraduates by asking them to rate their attraction and desire to affiliate with a man and a woman they were said to know from work.

"Imagine that you have just taken a job and that Jennifer (or John) is your immediate supervisor (or your peer, or your assistant)," study participants were told as they were shown a photo of a male or a female.

After seeing the photo and hearing the description of the person's role at work in relation to their own, participants were asked to use a 9-point Likert scale (1 is not at all, 9 is very much) to rate the extent to which they would enjoy going to a party with Jennifer or John, exercising with the person, dating the person and marrying the person.

Brown and Lewis found that males, but not females, were most strongly attracted to subordinate partners for high-investment activities such as marriage and dating.

"Our results demonstrate that male preference for subordinate women increases as the investment in the relationship increases," Brown said. "This pattern is consistent with the possibility that there were reproductive advantages for males who preferred to form long-term relationships with relatively subordinate partners.

"Given that female infidelity is a severe reproductive threat to males only when investment is high, a preference for subordinate partners may provide adaptive benefits to males in the context of only long-term, investing relationships---not one-night stands."

This poses a problem for not just for bright, motivated, and successful women but also for the gene pool of the human race. The genetic characteristics that make women bright, motivated, and successful are getting selected against more often than was the case in the past. In the Western industrial countries when women had far fewer opportunities to rise in status hierarchies and earn high incomes the women whose genetic potential was being suppressed appeared in more subordinate roles and hence were more attractive to successful men.

Of course there are limits to just how far the male attractiveness to lower status females will go - especially for marriage. One reason is simple: Money. Higher status females will bring more money to the marriage or the ability to work fewer hours to make the same amount of money as a lower status female makes working full time. So time for mommy duties can be greater with higher status females who are willing to work part-time. These facts have got to cross the minds of a lot of men who are looking at prospects.

Another point: This study used photos and no verbal interaction. In conversations brighter women may do better at raising the interest of men. They can be funnier and do a better job of picking up on cues about interests. Also, looks matter. Well, contrary to popular stereotypes the smarter women may have an edge on looks. intelligence and body symmetry are positively correlated. Body symmetry is also correlated with attractiveness. So brighter women are probably more attractive on average.

By Randall Parker    2004 December 13 01:13 PM   Entry Permalink | Comments (51)
2004 November 27 Saturday
Genetic Causes Of Infidelity Found In Twins Study

A comparison of the sexual histories of 1600 identical and non-identical twins found that genetic variations play a large role in influencing the tendency to infidelity among women.

"We found that around 40 percent of the influence on the number of sexual partners and infidelity were due to genetic factors," Professor Tim Spector, director of the Twin Research Unit at St Thomas' Hospital in London, told a news conference.

Identical twins whose twin has strayed have twice the normal chance of straying.

The findings mean that someone with a philandering twin is far more likely to philander themselves. The average risk of female infidelity is about 22%, says Spector, but those with an unfaithful identical twin have a risk of 44%.

Women tend to stray to hook up with higher status men.

The study, which was published in the journal Twin Research, suggests that a genetic predisposition towards female infidelity may have evolved because it was important in allowing women married to "low status" men surreptitiously to become pregnant by "high status" men.

"If female infidelity and number of sexual partners are under considerable genetic influence, as this study demonstrates, the logical conclusion is that these behaviours persist because they have been evolutionary advantageous for women," the researchers write in their scientific paper.

Female straying for higher status males offers a selective advantage that could have been selected for.

From an evolutionary perspective, a woman’s best short-term strategy would be to clandestinely pursue men with better genes.

Prof Spector points out that women tend to have affairs with men of higher status than their husbands. However, the system would break down, he said, if "everyone was unfaithful, because there would be no pair-bonding".

Three chromosomes were identified in this study as likely locations for genes that influence the odds of monogamy.

It lends strong support to theories advanced by evolutionary psychologists such as Steven Pinker, of Harvard University, who argue that human sexual behaviour is at least partly determined by natural selection and our genes.


Professor Spector’s team did not identify any particular gene that contributes to a tendency to infidelity, though they did pinpoint three regions on chromosomes 3, 7 and 20 that might harbour such genes. He believes that there are between 50 and 100 genes that contribute to a tendency to infidelity.

I predict with high confidence that once DNA testing becomes cheap then before entering into more committed relationships many men and women will surreptitiously take DNA samples from each other and have the DNA tested for genetic variations that contribute to infidelity and to other behavioral tendencies as well. If your man likely to be a hard worker in the long term but is too young have a long work track record? Test him for alleles that contribute to a work ethic. Are you afraid he might have a tendency toward violence? Test for violence-promoting genetic variations. Afraid she is going to cheat? Check hundreds of genes for polymorphisms that cause cheating other undesired behaviors and decide whether the odds of undesired future behaviors are higher than you find acceptable.

Once it becomes possible to alter the brains of adults to increase or decrease the appeal of promiscuity will some men and women come under pressure from their mates to go get a treatment to remove their urge to stray? It seems plausible.

Also, once the genetic variations for monogamy and promiscuity all become identified and it becomes possible to control which genetic variations one will pass on to one's offspring will people tend to choose genetic variations that increase or decrease the incidence of infidelity in relationships? My guess is that people will tend to choose genetic variations that increase the appeal of monogamy. One reason is that people who are going to have many children will tend to favor having children who will want to stick around to take care of their own kids. But I'm not certain on that point. What do you think?

Update: One point needs to be made about hereditability of behaviors: Just because twins are, on average 44% likely to engage in infidelity of their twin has done so does not mean that those are the real odds for each twin whose twin has engaged in infidelity. Suppose, for example, that there are 100 genes that influence whether, say, married people will engage in extra-marital affairs. Well, one pair of twins might have half those genes in variations that predispose toward infidelity. Yet another pair of twins might have 75 of those 100 genes all in versions that predispose for infidelity and still another pair of twins might have all 100 of those genes in versions that predispose for infidelity.

The problem with studies of the behavior of groups twins is that such studies probably understate the extent to which genes can cause particular behaviors. There are people who have a set of genetic genes that pull them in opposing directions. But then there are people who have sets of genetic variations that very strongly pull them in particular directions. Take the twins in this study of infidelity. The twins where each twin engaged of infideilty probably, on average, have more genetic variations that predispose them for infidelity than do the twins where only one of the two twins in a pair engaged in infidelity.

You will see a lot of news reports claiming that the more sophisticated view is to see genes and environment as interacting to cause behaviors. That is true. But that argument is typically made to assure everyone that we really still each have ultiimate control over what we do and that we all have free will. But twins studies understate the extent to which genetic variations influence behavior because those studies deal with groups averaged together. Once DNA sequencing becomes cheap and each person in studies of human behavior can have their complete genome sequenced I expect to see many combinations of genetic variations found that exert extremely strong and even uncontrollably strong influences on human behavior.

Update II:

Women’s fidelity has come under fire at the University of Chicago. Some claim that women are naturally endowed with cheating hearts, and they are pointing to the size of men’s testicles as proof.

A Chicago research team, led by Dr. Bruce Lahn, found that the intensity of sexual competition in a variety of primate species is directly related to the size of males’ testicles. After obtaining DNA sequences from the SEM2 gene from 12 species of primates, including humans, the team examined the evolution of these primates’ sperm.

“We found that the rate of evolution is much higher—that is, the gene has undergone much more dynamic changes—in primate species with promiscuous females than in primate species with monogamous females,” Lahn said. “In other words, when males have to compete more in the game of fertilization, their semen protein has to make more innovations along the way.”


Human testicles fall somewhere in the middle of chimp and gorilla testicles in size. This suggests that women’s fidelity patterns likewise fall somewhere in between these two species, so that women are neither as faithful as gorillas nor as naughty as chimps.

Lahn and colleagues found that the SEMG2 gene in more promiscuous species makes semen more viscous to create a chemical chastity belt against competing sperm from other males.

Lahn's group studied semenogelin, a major protein in the seminal fluid that controls the viscosity of semen immediately following ejaculation. In some species of primates, it allows semen to remain quite liquid after ejaculation, but in others, semenogelin molecules chemically crosslink with one another, increasing the viscosity of semen. In some extreme cases, semenogelin's effects on viscosity are so strong that the semen becomes a solid plug in the vagina. According to Lahn, such plugs might serve as a sort of molecular “chastity belt” to prevent fertilization by the sperm of subsequent suitors, though they might also prevent semen backflow to increase the likelihood of fertilization.

Lahn and his colleagues compared the SEMG2 gene, which contains the blueprint for semenogelin, from a variety of primates. They began by sequencing the SEMG2 gene in humans, chimpanzees, pygmy chimpanzees, gorillas, orangutans, gibbons, macaques, colobus monkeys, and spider monkeys. These species were chosen because they represent all the major mating systems. These include those in which one female copulates with one male in a fertile period (such as gorillas and gibbons); those in which females copulate highly promiscuously (such as chimpanzees and macaques); and those in which mating practices fall somewhere in between (such as orangutans where a female will copulate with the dominant male, but may also copulate with other males opportunistically).

Update III: Over on the Gene Expression blog Godless Capitalist reports on Jared Diamond accepting the existence of variations in testes size as a function of racial and ethnic group. This is a sign that selective pressures caused by infidelity have not been uniform across the entire human race down through history since humans spread out across the planet. It seems quite possible that some or all of the genetic variations mentioned at the top of this post that influence infidelity vary their distribution along with the genetic variations that cause large testis size.

By Randall Parker    2004 November 27 04:40 PM   Entry Permalink | Comments (8)
2004 September 28 Tuesday
Sexy Voice Key To Large Sex Life

Gordon G. Gallup, Jr., Susan M. Hughes and Franco Dispenza have found that people with sexy voices get more sex and have more symmetrical body shapes.

In "Ratings of voice attractiveness predict sexual behavior and body configuration," published in the September issue of Evolution and Human Behavior, published by Elsevier, Susan Hughes, Franco Dispenza, and Gordon Gallup of the University's department of psychology tested 149 men and women by having them listen to recorded, neutral voices counting from 1 to 10. They were then asked to rate the anonymous voices on a scale from "very unattractive" to "very attractive." The results were compared to surveys and morphological measurements taken among the speakers. Researchers discovered that people whose voices are judged to be attractive tend to have sexual intercourse at an earlier age, have more sexual partners than those with voices rated less attractive, and are more prone to sexual infidelity. They also have more sex partners among people involved in other relationships.

"In short," Gallup said, "ratings of voice attractiveness are correlated with promiscuity in both men and women."

The fact that people with more symmetrical bodies have sexier voices is especially interesting. This suggests that the quality of development of a fetus translates into not just a more attractive symmetrical appearance but also into a throat shape that creates more pleasing vocal sounds.

The full paper is on-line.(PDF format)

We investigated the relationship between ratings of voice attractiveness and sexually dimorphic differences in shoulder-to-hip ratios (SHR) and waist-to-hip ratios (WHR), as well as different features of sexual behavior. Opposite-sex voice attractiveness ratings were positively correlated with SHR in males and negatively correlated with WHR in females. For both sexes, ratings of opposite-sex voice attractiveness also predicted reported age of first sexual intercourse, number of sexual partners, number of extra-pair copulation (EPC) partners, and number of partners that they had intercourse with that were involved in another relationship (i.e., were themselves chosen as an EPC partner). Coupled with previous findings showing a relationship between voice attractiveness and bilateral symmetry, these results provide additional evidence that the sound of a person’s voice may serve as an important multidimensional fitness indicator.

A sexy voice might be more important for a female than a male. Males might be better off with bigger shoulders.

It is interesting that voice attractiveness was a better predictor of sexual behavior in females than WHR was. The best predictor of promiscuity (as measured by number of sexual partners) in males was SHR, whereas in females, it was voice attractiveness. As shown in Table 2, the correlations between opposite-sex ratings of voice attractiveness and sexual behavior in females were consistently higher than those found for WHR and sexual behavior. However, just the opposite was true for males (see Table 1). Among males, SHR was a better predictor of sexual behavior than voice was. For example, whereas opposite-sex voice attractiveness accounted for 13% of the variance in promiscuity among males, SHR accounted for 28% of the variance in male promiscuity. The same sex differences held for the relationship between voice and body configuration. Male SHR accounted for more variance (25%) in opposite sex ratings of voice attractiveness than did female WHR (14%).

Perhaps people with unsexy voices should avoid talking much in bars.

By Randall Parker    2004 September 28 02:36 AM   Entry Permalink | Comments (10)
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