June 18, 2012

Sex and Gender: Different but the Same

A new line of biological research turns the model of the interaction between the brain, sex and gender upside down.

I have written quite extensively on the research on sex and gender on this blog, focusing on both the biological and socio-cultural factors that may or may not influence gender development.

What I have learned from all of this is (1) that gender roles and behavior are predominantly influenced by cultural factors, while (2) sex identity (the sense of being a man, a woman or neither) has a much stronger biological basis.

The story so far.

So far biological research on the interaction between the body, the brain, the embodied sex and gender expressions has been based on the idea that sex identity (the sense of self) is based in unique properties of the brain.

That is: Due to prenatal hormonal influences, the brains of men and women are different, and this makes them men or women, not only on the outside, but also -- to a more limited extent -- psychologically.

Secondly, natural scientists tend to believe that much of our gendered behavior is partly influenced by this core identity, in the sense that women are -- for instance -- more likely to express empathic traits and men analytic capabilities, on average and statistically speaking.

All serious researchers in this field accepts that much of our gendered behavior is heavily influenced by culture as well, though. I have so far seen only one study that tries to prove that women prefer pink for biological reasons. (God, that was a stupid study!!!)

I have become more and convinced that much of what we consider "natural" behavior gender wise, is indeed cultural.

Much of this is caused by the fact that I live in  a country where women are found in all types of work. The fact that women now dominates universities tells me that the old idea that women are less analytical than men makes little sense.

It is not that long ago that a woman who wanted to go to university would be diagnosed as a hysteric and sent to a sanatorium.

Why do not men and women differ more from each other?

The new radical approach to sex and gender does not ask what makes men and women behave differently.

These researchers ask the following questions: Given the fact that men and women differ significantly body wise (size, muscle strength, hormonal balance, sex organs, the ability to develop a fetus etc), why is their behavior so similar?

Yeah, you heard me! The biologcial mystery of the day is the equality of the sexes, not the fact that they are different.


In a recent issue of the New Scientist, Kayt Sukel uses bikes as an analogy.

If you compare a chunky mountain bike with a lightweight road bike, you will see that their different structure will influence the way their capabilities and the way they are used:

"To compensate for the mountain bike's greater resistance, you have to pedal harder to reach the same speed; one difference makes you introduce another to achieve the same output."

Hence the idea is that men and women behave the same, because their brains are different: "In brain terms, while certain circuits may be shaded pink or blue, that would not stop the output, or behavior, being a uniform purple."

The keyword is compensation

I know that a lot of people believe that men must be significantly more aggressive than men due to the production of testosterone. Men produces 20 times as much testosterone as women, and the hormone is known to generate aggression in many animals.

But sexist stereotypes aside, in my experience men are not t more aggressive than women. Men tend to act out physically instead of psychologically, that is true, but then again they have the body mass to get away with it. Women can be mad as hell, if the culture allows them to express such feelings. So how do you explain the discrepancy between their use of hormones?

Remember that here are two sides to hormones: production and reception. The amount of hormones you are able to put into action is just as important as the amount you produce. And since the brains of men and women have different ways of making use of hormones, the quantity only tells us so much.

Indeed, neuroscience is often criticized for putting too much weight on the very average differences between the sexes. As Sukel points out, there is more variability within each sex than between men and women as a whole.

de Vries

The first one to make people notice the so-called compensation theory was Geert de Vries. In the 1980s he found that there were small differences in behavior between male and female prairie voles as regards nursing behavior, in spite of the females having many more receptors in the brain for vasopressin, a brain signaling molecule that been linked to parental care.

Sukel points out that the female voles' maternal devotion was clearly triggered by the hormonal changes of pregnancy. So the males' brains seemed to be compensating for the lack of pregnancy hormones.

Reproduction with a cost

Margareth McCarthy at the University of Maryland School of Medicine puts it this way:

"Many of the sex differences we see in the brain are there to help males and females develop different reproductive strategies. Bu those differences also carry with them some constraints. Males have high testosterone, female have cycles of various hormones. And those hormones come with costs with the regards to behaviors outside reproduction."

Larry Cahill, a neuroscientist who researches human sex differences at the University of California, Irvine. has done a review of several brain-scanning studies. Many of them show differences in men and women that are not accompanied by differences in their performance.


The New Scientist notes that

"Cahill himself may have found evidence of compensatory circuits at work, involving the amygdalae, a pair of almond-shaped structures deep within the brain thought to be involved in the processing and memory of emotional reactions.

Cahill's group showed that even when the brain is at rest, amygdala activity is different in men and women (Neuroimage, vol 30, p 452).   

That made neuroscientists sit up and take notice, because most imaging studies require resting activity levels to be subtracted from levels seen during experimental tasks in order to reveal changes caused by the task.

Given these findings, important results may be going unseen because at the moment men and women's results tend not to be analysed separately.

Cahill thinks the difference in amygdala activity could be a compensatory mechanism to make up for differences in testosterone levels.

'There are instances where everyone agrees that there is no sex difference on the behavioural level. But that doesn't mean there isn't a sex difference in the brain,' he says. 'It remains possible that the equal behaviour was achieved in different ways.'"

Imperfect world

I believe the reason this way of thinking seems so strange is that most of us has an image of the human body as a perfectly balanced system developed by a master engineer, being that God or Mother Nature.

But if you look at this from an evolutionary perspective, it makes perfect sense for nature to keep a system that actually works, and then find ways around other problems that might be caused by this solution.


The New Scientist does not discuss compensatory theory and the development of sex identity.

Gert de Vries (the man mentioned above) has looked into the brains of transsexuals, however. He and his colleagues found  a region of the hypothalamus that is about 50 percent larger in men than in women, and almost 60 percent larger in men than in male-to-female transsexuals.

Those who have followed this blog will know that I have spent a lot of time on such research, but also on social science explaining how small the differences are in female and male behavior.

Indeed, the battle of our perception of sex and gender has in many ways become a battle between the natural sciences on the one hand and the social sciences and the humanities on the other. The first focus on biology, the other on culture and semiotics. The first focus on the differences, the other on the similarities between the sexes.

(It is a if-all-you-have-is-a-hammer-everything-becomes-a-nail kind of thing).

Due to my own gender dysphoria I am convinced that at least some transgender conditions, my own included, are anchored in biology.

But at the same time I see that most of the arguments used in both outside and inside transgender circles are based on cultural stereotypes that have no basis in reality  (like in the argument that true transsexuals are more adept at holding their handbags in a natural feminine way than perverted autogynephiliacs).

The nature/nurture puzzle

I must admit that I have found it very hard -- intellectually -- to reconcile my own in-the-bones conviction that I have a strong "inner woman" with the amazing similarity between men and women I see around me.

As soon as I think I have found a trait that seems uniquely male or female, up pops someone who proves me wrong. And because of this it is very hard to explain what this feeling of "being a woman" actually entails, even if it is persistent,  strong and real.

The compensatory theory may provide a solution to this puzzle.

Even if your organism tries to compensate for the sexual differences, the brains of men and women are not the same, which must have some repercussions on how we see the word and ourselves. This means that the gender dysphoria felt by both female and male bodies may indeed be caused by them having brains more similar to the opposite biological sex.

And even if the culturally defined rules for how men and women ought to behave have no root in biology, the need to be validated or affirmed as a member of your real sex might have. Because of this transgender will often seek to find an expression of their inner self by using the symbols found in the culture around them.

They simply want to be loved for who they are.

Discuss crossdreamer and transgender issues!