According to a new paper, the brains of male-to-female transexuals are no more “female” than those of men. (…) But is it so simple? (..)

Structural MRI scans were used to compare the size of various brain structures between three groups of volunteers: heterosexual men, heterosexual women and the transexuals (or “MtF”s as I will call them for short) who were diagnosed with gender dysphoria and were “genetically and phenotypically males”.

There were 24 in each group, which makes it a decent sized study. None of the MtFs had started hormone treatment yet, so that wasn’t a factor, and none of the women were on hormonal contraception.

The scans showed that the non-transsexual male and female brains differed in various ways. Male brains were larger overall but women had increases in the relative volumes of various areas. Male brains were also more asymmetrical.

The key finding was that on average, the MtF brains were not like the female ones. There were some significant differences from the male brains, but they weren’t the same differences that distinguished the females from the males. (…)

There could be all kinds of chemical and microstructural differences that don’t show up on these scans.

There are lots of people with severe epilepsy, for example, whose brains clearly differ in some major way from people without epilepsy, yet they look completely normal on MRI.

{ Neuroskeptic | Continue reading }

photo { Bruce Davidson }

A leading theory of romantic love is that it functions to make one feel committed to one’s beloved, as well as to signal this commitment to the beloved (Frank, 1988). Because women tend to be skeptical of men’s commitment, this view entails that men may have evolved to fall in love first, in order to show their commitment to women.

Using a sample of online participants of a broad range of ages, this study tested this sex difference and several related individual difference hypotheses concerning the ease of falling in love. There was mixed evidence for sex differences: only some measures indicated that men are generally more love-prone than are women. We also found that men were more prone to falling in love if they tended to overestimate women’s sexual interest and highly valued physical attractiveness in potential partners. Women were more prone to falling in love if they had a stronger sex drive.

{ Evolutionary Psychology | Continue reading | PDF }

photo { Richard Avedon }

Most shocking among UNICEF’s findings is that, despite pervasive discrimination against women, female-headed households in the poorest countries have, on average, better health and economic outcomes than male-headed, two-parent households. Taken together, these statistics suggest that men are nothing less than a complete waste of national resources; one might even wonder why the development community is devoting itself to such slow-motion efforts as microloans to women when the wholesale isolation or expulsion of men (after their sperm is collected and stored) could lift these countries out of poverty much faster.

{ The New Atlantis | Continue reading }

Women today are entering adulthood with more education, more achievements, more property, and, arguably, more money and ambition than their male counterparts. This is a first in human history, and its implications for both sexes are far from simple.

{ CATO Unbound | Continue reading }

photo { Garry Winogrand, Opening, Frank Stella Exhibition, The Museum of Modern Art, 1970 }

Women have breasts, whereas men have flat chests (but still with nipples on them). Why?

Women are the only primates who are busty all the time, even when they aren’t nursing. Alternative theories exist, but most scientists think breasts are an evolutionary trick for snagging men; though they’re actually filled with fat, not milk, they signal a woman’s bountiful ability to feed her children.

Breasts also help men figure out who to pursue to achieve reproductive success. Prepubescent girls don’t have breasts, and the breasts of post-menopausal women are often shrunken and saggy. A full, buoyant bosom can therefore demonstrate fertility.

Men aren’t trying to trick women into thinking they can breastfeed, so they don’t have breasts. They do, however, have nipples: This is because the genes that code for nipple development switch on in utero, and at a very early embryonic stage — even before the genes gear up that turn us into males or females. (…)

Whatever your sex, everyone starts off as a woman in the womb. For the first several weeks a developing embryo follows a “female blueprint,” from reproductive organs to nipples. Only after about 60 days does the hormone testosterone kick in (for those of us with a Y chromosome), changing the genetic activity of cells in the genitals and brain. But by then those mammary papillae aren’t going anywhere.

{ Men vs. Women: Key Physical Differences Explained | Continue reading }

images { 1 | 2 }

{ Suicide methods differ between men and women. Men nearly twice as likely as women to use a method that disfigures the face or head when taking their own lives. | EurekAlert }

What could be wrong with a gentleman opening a door for a lady? According to some social psychologists, such acts endorse gender stereotypes: the idea that women are weak and need help; that men are powerful patriarchs. Now a study has looked at how women are perceived when they accept or reject an act of so-called “benevolent sexism”* and it finds that they’re caught in a double-bind. Women who accept help from a man are seen as warmer, but less competent. Women who reject help are seen as more competent, but cold.

{ BPS | Continue reading }

“The typical view is that women take less risks than men, that it starts early in childhood, in all cultures, and so on,” says Bernd Figner of Columbia University and the University of Amsterdam. The truth is more complicated. Men are willing to take more risks in finances. But women take more social risks—a category that includes things like starting a new career in your mid-thirties or speaking your mind about an unpopular issue in a meeting at work.

It seems that this difference is because men and women perceive risks differently. That difference in perception may be partly because of how familiar they are with different situations, Figner says. “If you have more experience with a risky situation, you may perceive it as less risky.” Differences in how boys and girls encounter the world as they’re growing up may make them more comfortable with different kinds of risks.

Adolescents are known for risky behavior. But in lab tests, when they’re called on to think coolly about a situation, psychological scientists have found that adolescents are just as cautious as adults and children.

{ APS | Continue reading }

artwork { Fra Filippo Lippi, Portrait of a Woman with a Man at a Casement, ca. 1440–44 }

University of Minnesota Medical School and College of Biological Sciences researchers have made a key discovery showing that male sex must be maintained throughout life.

The research team, led by Drs. David Zarkower and Vivian Bardwell of the U of M Department of Genetics, Cell Biology and Development, found that removing an important male development gene, called Dmrt1, causes male cells in mouse testis to become female cells.

In mammals, sex chromosomes (XX in female, XY in male) determine the future sex of the animal during embryonic development by establishing whether the gonads will become testes or ovaries.

“Scientists have long assumed that once the sex determination decision is made in the embryo, it’s final,” Zarkower said. “We have now discovered that when Dmrt1 is lost in mouse testes – even in adults – many male cells become female cells and the testes show signs of becoming more like ovaries.”

{ EurekAlert | Continue reading }

It is well recognized that there are consistent differences in the psychological characteristics of boys and girls; for example, boys engage in more ‘rough and tumble’ play than girls do.

Studies also show that children who become gay or lesbian adults differ in such traits from those who become heterosexual – so-called gender nonconformity. Research which follows these children to adulthood shows that between 50 to 80 per cent of gender nonconforming boys become gay, and about one third of such girls become lesbian. (…)

The team followed a group of 4,000 British women who were one of a pair of twins. They were asked questions about their sexual attractions and behavior, and a series of follow up questions about their gender nonconformity. In line with previous research, the team found modest genetic influences on sexual orientation (25 per cent) and childhood gender nonconformity (31 per cent).

{ EurekAlert | Continue reading }

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Anyway. There are two essential truths about girl-on-girl friendship: 1) underneath the harsh hate-tokes, girls really, really, really love each other and understand that we’re part of an all-powerful pussy tribe bound by wisdom and empathy and being on the same period cycle and 2) we still want to kill and eat each other (not in a sexy way). Here’s why:

• GIRLS WANT TO (BE THE ONLY GIRL WHO GETS TO) FUCK

• GIRLS WANT EACH OTHER’S BODIES, FACES, CLOTHES, LIVES

• GIRLS CAN’T JUST HANG OUT

{ Vice | Continue reading }

photo { Inez van Lamsweerde & Vinoodh Matadin }

Is male libido the ultimate cause of war?

Across four experiments Lei Chang and his team showed that pictures of attractive women or women’s legs had a raft of war-relevant effects on heterosexual male participants, including: biasing their judgments to be more bellicose towards hostile countries; speeding their ability to locate an armed soldier on a computer screen; and speeding their ability to recognise and locate war-related words on a computer screen.

Equivalent effects after looking at pictures of attractive men were not found for female participants.

{ BPS | Continue reading }

What Makes a Team Smarter? More Women.

There’s little correlation between a group’s collective intelligence and the IQs of its individual members. But if a group includes more women, its collective intelligence rises. (…)

The standard argument is that diversity is good and you should have both men and women in a group. But so far, the data show, the more women, the better. (…)

Many studies have shown that women tend to score higher on tests of social sensitivity than men do. So what is really important is to have people who are high in social sensitivity, whether they are men or women.

{ Harvard Business Review | Continue reading }

While it is recognized that Barbie dolls are perceived as feminine and Action figures as masculine, less is considered about the gender associations related to everyday items like the food we choose to eat. A series of studies reveal for instance that sour dairy products tend to be perceived as relatively feminine, whereas meat tends to be perceived as relatively masculine. Men are inclined to forgo their intrinsic preferences to conform to a masculine gender identity. Women, on the other hand, appear to be less concerned with making gender-congruent choices.

{ SAGE | Continue reading }

The normal human ratio is around 105 boys for every 100 girls, a natural evolutionary ratio that takes into account the fact that more boys tend to die before reaching adulthood. But in China today, the ratio is 121 boys for every 100 girls; in India the ratio is 112 boys for every 100 girls. (…)

In her thorough and compelling new book, Unnatural Selection, Hvistendahl explains why these trends will have far-reaching effects. She argues that the sex imbalance could prove devastating to social stability across the developing world, sparking crime, human trafficking, and - if history is any guide - even war.

{ The National | Continue reading }

photo { Sally Mann }

Why is it that men so often self-destruct? (…) We men just make bad decisions. We can’t help it. We’re men.

Women, on the other hand, do almost everything better. We’ve known this intuitively for a long time. If you didn’t, just ask your wife or your mother. But now there’s a raft of evidence that suggests women are better at everything — including investing.

A new study by Barclays Capital and Ledbury Research found that women were more likely to make money in the market, mostly because they didn’t take as many risks. They bought and held. Women trade this way because they aren’t as confident — or perhaps as overconfident — as men, the study found.

{ MarketWatch | Continue reading }

photo { Katy Grannan }

Affecting up to 80 percent of women, PMS is a familiar scapegoat. But women are affected by their cycles every day of the month. Hormone levels are constantly changing in a woman’s brain and body, changing her outlook, energy and sensitivity along with them.

About 10 days after the onset of menstruation, right before ovulation, women often feel sassier, Brizendine told LiveScience. Unconsciously, they dress sexier as surges in estrogen and testosterone prompt them to look for sexual opportunities during this particularly fertile period.

A week later, there is a rise in progesterone, the hormone that mimics valium, making women “feel like cuddling up with a hot cup of tea and a good book,” Brizendine said. The following week, progesterone withdrawal can make women weepy and easily irritated. “We call it crying over dog commercials crying,” Brizendine said.

For most women, their mood reaches its worst 12-24 hours before their period starts. (…)

Over the course of evolution, women may have been selected for their ability to keep young preverbal humans alive, which involves deducing what an infant or child needs — warmth, food, discipline — without it being directly communicated. This is one explanation for why women consistently score higher than men on tests that require reading nonverbal cues. Women not only better remember the physical appearances of others but also more correctly identify the unspoken messages conveyed in facial expressions, postures and tones of voice, studies show. (…)

Brain-imaging studies over the last 10 years have shown that male and female brains respond differently to pain and fear. And, women’s brains may be the more sensitive of the two. (…)

“A women’s sex drive is much more easily upset than a guy’s,” Brizendine said.

For women to get in the mood, and especially to have an orgasm, certain areas of her brain have to shut off. And any number of things can turn them back on.

A woman may refuse a man’s advances because she is angry, feeling distrustful — or even, because her feet are chilly, studies show.

{ LiveScience | Continue reading }

related { According to research, the more housework men do, the happier their wives are. }

Very few studies have used an evolutionary approach to help understand fictional heroes, and none have directly addressed how the sex of the author might influence the characteristics of the hero. If evolved behavioral differences in the sexes have influenced the subconscious tendencies of human males and females, these differences should be reflected in the fictional characters each creates. Based on sexual selection and inclusive fitness theory, I predicted that females will be more likely than males to create heroes who have family members, and that family members will be more important in the plotlines of female-generated stories. Information collected from twenty children’s fantasy novels published after 1994 display the predicted trends.

In addition, male authors often created parents who were problematic (insane, irresponsible, or evil), something the female authors never did.

{ Victoria Ingalls, The Hero’s relationship to family: Sex differences in hero characteristics, 2010 | Continue reading | PDF }

artwork { Nina Hoffmann }

Who is harder to raise, sons or daughters? I’ve asked by a show of hands and with iClickers, over the years, and the room of 750 is almost unanimous: daughters are harder to raise. (…)

So then I show them this.

It is a graph of maternal longevity based on the number of sons or daughters they have. This data was based on a historical population from Finland from 1640-1870 using church records (Helle et al 2002). As you can see, the more sons mothers bear, the shorter their lifespans.

{ Context and Variation | Continue reading }

A meta-analysis finds gender differences in sexual attitudes and behaviors are smaller than you may think. (…)

Synthesizing the results of more than 700 studies, psychologists Jennifer Petersen and Janet Shibley Hyde of the University of Wisconsin-Madison report “men and women are more similar than they are different in terms of sexuality.” They found only small differences between males and females in 22 of 30 common sexual behaviors and attitudes — and no differences at all for another four.

The sexual behaviors surveyed included frequency of intercourse, number of partners, extramarital sex and condom use. A separate list examined sexual attitudes, including permissiveness, anxiety and guilt, satisfaction with one’s sex life and views regarding homosexuality.

The researchers found substantial gender differences in two categories: reported masturbation and pornography use. (…)

Overall, the report provides at least qualified support for several theoretical models — including evolutionary psychology, which contends that men have evolved to desire multiple sex partners because it increases their odds of passing their genes down to the next generation. (Women, on the other hand, “have evolved to disapprove of casual sex because it may yield fathers who do not provide for them and their children.”) The fact that men reported more permissive sexual attitudes and engaged in more sexual behavior is consistent with this notion.

{ Miller-McCune | Continue reading }

related { Women who are sexually satisfied are also happier, no matter their age, a study suggests }

Women, according to countless studies, are twice as prone to anxiety as men. When pollsters call women up, they always confess to far higher levels of worry than men about everything from crime to the economy. Psychologists diagnose women with anxiety disorders two times as often as men, and research confirms—perhaps unsurprisingly—that women are significantly more inclined toward negative emotion, self-criticism, and endless rumination about problems. (…)

In reality, the idea that women are “naturally” twice as anxious as men is nothing more than a pernicious illusion. (…)

A few recent studies have indicated that the hormonal differences between the sexes really do make women a touch more biologically inclined toward anxiety than men. (…) Just how big a role these biological factors play in human women’s anxiety isn’t yet clear.

But one thing we do know for certain is that the way we raise children plays a huge role in determining how disposed toward anxiety they are later in life, and thus the difference in the way we treat boys and girls explains a lot about the heightened nerves we see in many adult women.

{ Slate | Continue reading }

artwork { Willem de Kooning, Woman, 1951-52 | Oil and pencil on paperboard }