There are many biological differences between male and female brains

Posted on June 27, 2018 | By Kåre Fog
According to Lise Eliot, a professor of neuroscience, “there is absolutely no difference between male and female brains.” She said so onstage on June 25th, 2018 at the Aspen Ideas Festival, which was co-hosted by the Aspen Institute and The Atlantic.

That is a very strange statement from a university professor. It would be similar to saying that “there is absolutely no difference between the physical strength of men and women.” If somebody said so, we would at once know that this is ridiculous. But what Eliot said last Monday, is equally ridiculous.

Consider what other neuroscientists say. There was, for instance, a review article in Nature Reviews Neuroscience, by Larry Cahill, in 2006. He writes: "Sex differences exist in every major part of the brain" and "the still widespread assumption that sex influences are negligible cannot be justified, and probably retards progress in our field". What Cahill wrote, is confirmed by many older and more recent articles, for instance this article in The Scientist from 2015.

Eliot said neuroscientists have yet to find a single circuit that’s wired differently between men and women – how strange of her to say that. A recent study investigated nerve connections in the brain and found that 54 % of the studied connections show significant differences between the sexes.

It is also strange that she does not refer to the preoptic nucleus in the part of the brain called the hypothalamus. Here is a group of nerve cells that is much larger in males than in females – in research animals as well as in humans. This cell cluster has something to do with sexual behavior, so of course it has to be different in men and women. And it is not because of some effect of upbringing or social norms – because it is the same difference as in animals.

A few people feel that they are "born in the wrong body" – they feel subjectively that they are females, although they have a male body, or vice versa. Some of these persons become transgender-persons and accept various treatments to obtain this transformation. To support the conception that they are really different from ordinary people, they may cite recent investigations demonstrating that certain features in their brain are more like in the desired sex, rather than like the sex indicated by the body. Maybe transgender people will be sad to hear Eliot claim that this is all just an illusion – and to hear that there is absolutely no difference between male and female brains.

In 2014-2015 a study group led by Daphna Joel used advanced statistical analyses to find out if there are any consistent differences between men and women in behavior and in brain structure. They found that only a very, very low percentage of all persons are clearly masculine or clearly feminine in these areas. However, they have been criticized heavily for using statistical methods that tend to find no differences. If the same methods were used for instance for analyses of photographs of human faces, the result would be that very few faces were clearly masculine or clearly feminine. But everybody knows that if you look at a face photograph, you can in the vast majority of cases see if the person is a man or a woman. So the statistical procedure used had less ability to observe differences than any layperson who looks at the person.
Therefore, this study was criticized by many colleagues; a popular article about the criticism is found here.

Why did Joel and coworkers publish such a misleading study? They could have written that using a very strict type of analysis, very few persons are markedly characteristic for one sex in all features simultaneously. But instead, they wrote that "human brains cannot be categorized into two distinct classes: male brain/female brain". As explained above this is not true – already by looking at the preoptic nucleus, brains can be so categorized. So why did they write something that is simply not true?

Probably for the same reason that Lise Eliot says something that is obviously not true – namely, for ideological reasons. I guess that in the circles where Daphna Joel moves and Lise Eliot moves, it is not politically correct to assume that the two sexes are inherently different in anything else than the sexual organs – because, if such differences were inherent, then you could justify uneven distribution of the sexes in many cases, for instance that there are fewer composers or chess geniuses among women than among men. In these circles you cannot accept that divergence from a 50/50 distribution of the sexes in any job sector or any other sector of society may sometimes be explained by biologically determined traits, because if such divergences were justified, claims about discrimination would evaporate. In such circles, the fact that the sexes are not evenly distributed throughout society is taken to prove that evil discriminating men, or evil discriminating social structures, abound everywhere. In these circles it seems to be so important to maintain this belief, that any scientific evidence speaking against it is rejected – just as any scientific evidence for Darwinian evolution is rejected out of hand by Christian fundamentalists.

If a scientist claims that an uneven distribution of the sexes in some sector – in a board of directors, or in a political assembly, or in any kind of business or institution – can only be due to sex discrimination, then that scientist should adhere to scientific principles and not make such claims before it has been scientifically demonstrated that there is indeed discrimination in the case that he or she studies, rather than just different representations in different fields.

By the way, it will not help to postulate, as Eliot does, that differences between sexes are best explained by nurture. We have societies where you can hardly do more than has already been done to eliminate cultural norms about sex differences. To some extent, this is true of the Scandinavian countries where the differences between sexes in preferred occupations none the less is larger than everywhere else. For instance in Norway, about 90 % of all nurses are women, and 90 % of all engineers are men. An even stronger example is the Israeli kibbutzim in the 1930s, where all inputs that could stimulate development of sex differences in children were systematically removed – and where the children nevertheless grew up and showed large sex differences and traditional sexually diversified attitudes.

It is very, very sad that the willingness to mislead about what science says is so strong here. When a professor of neuroscience in public claims something that is diametrically opposite to existing knowledge, then this is a crime against science – in science it is unacceptable to go against what others have found without bringing solid arguments that these others are wrong.

If we accept that scientists just say what is politically correct, then the public can no longer have any trust in science, that is, there will no longer be any purpose to have science. This kind of behavior is a reversal of the movement towards enlightenment in Europe 500 – 400 years ago, which led to the rise of science and hence to enormous benefits for society. The respect for scientific thinking is on its way down again, and the consequences for society at large may be grave.

June 26th 2018
Kåre Fog

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Den oprindelige online-tekst i The Atlantic blev senere (inden 11 dage efter publiceringen) ændret på en række punkter:

DEN OPRINDELIGE OVERSKRIFT " There Is No Biological Difference Between Male And Female Brains "

ER NU ÆNDRET TIL DETTE: "Are Male and Female Brains Biologically Different?"

DEN OPRINDELIGE TEKST:
" It's tempting to think the differences between men and women are hard-wired into our biology, but neuroscience shows that we're more alike than we think."

ER NU ÆNDRET TIL:

"The scientific debate around this question keeps raging, but one neuroscientist says we’re more alike than we think.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
Pop neuroscience has long been fascinated with uncovering secret biological differences between male and female brains.

DENNE TILFØJELSE ER INDFØJET:
"The question of whether men and women have innately different brains rarely fails to get people riled up. "

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
Just last year, the Google engineer James Damore caused an uproar after publishing a manifesto detailing the various ways women were biologically different from men.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
But Lise Eliot, a professor of neuroscience at the Chicago Medical School and the author of Pink Brain, Blue Brain, says that anyone who goes searching for innate differences between the sexes won’t find them.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
“People say men are from Mars and women are from Venus, but the brain is a unisex organ,” she said onstage Monday at the Aspen Ideas Festival, which is co-hosted by the Aspen Institute and The Atlantic.

MAN HAR SLETTET SÆTNINGEN " We have the exact same structures,”

MAN HAR SLETTET SÆTNINGEN.“There is absolutely no difference between male and female brains.”

MAN HAR SLETTET SÆTNINGEN:
Eliot said neuroscientists have yet to find a single circuit that’s wired differently between men and women, and that differences between sexes are best explained by nurture, not nature.

DET ER LAVET DENNE NYE TEKST: That’s a bold statement, and one science is divided on. It seems to depend on what exactly is being measured. For example, a large study in the U.K. found that many regions of men’s brains were larger than women’s, and that women on average had thicker cerebral cortices. What does that mean for how the brain works? Unclear.

DET ER LAVET DENNE NYE TEKST: Another study found that “averaged across many people, sex differences in brain structure do exist, but an individual brain is likely to be just that: individual, with a mix of features,” as New Scientist reported in 2015.

DET ER LAVET DENNE NYE TEKST: But there’s no doubt that whatever their brains look like, behavior and school performance differences between men and women are strongly shaped by socialization.

DETTE TEKSTSTYKKE ER BORTSET FRA DET PÅPEGEDE IKKE ÆNDRET:
Eliot said that Damore has a misunderstanding [I DEN OPRINDELIGE TEKST STOD DER: "deep misunderstanding"] of neuroscience and that his letter overstated [I DEN OPRINDELIGE TEKST STOD DER: " grossly overstated"] the role of testosterone in male and female bodies. While testosterone is linked to aggression, it doesn’t offer a universal explanation for male behavior.

DENNE SÆTNING I DEN OPRINDELIGE TEKST ER SLETTET: “The average male is more aggressive than two-thirds of females,” she said, “but that also means one-third of females are more aggressive than the average male.”

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
Eliot also said that everyone, regardless of sex, can be competitive or aggressive, but males and females might have different ways of expressing those traits based on social norms.

DENNE SÆTNING ER SLETTET:
"“We keep looking for a biological difference, finding it, it inevitably gets discredited, and yet we still seem so eager to find another one,” she said."

DETTE TEKSTSTYKKE ER BORTSET FRA DET PÅPEGEDE IKKE ÆNDRET:
Eliot blames academia and the media in part for the cycle [DER ER LAVET FØLGENDE TILFØJELSE:] "that leads to the ongoing argument over biological brain differences".

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
Because most scholars know that any small statistical difference between men and women will make headlines, academics, desperate for funding and attention, often focus studies on gender disparities. “You go back to data, analyze it for sex, and if you find a difference, then guess what: You have another paper,” Eliot said.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
She said that even scientifically indisputable differences, such as the oft-cited statistic that male brains are 10 percent bigger than female brains, don’t mean anything. All of men’s organs are bigger on average, but that doesn’t mean they function differently.

FØLGENDE SÆTNING ER SLETTET: "Eliot said that it’s important to debunk efforts to prove that female brains are different if we want to disrupt current power structures."

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
If scientists and academics were to begin with the premise that men and women are equally capable, Eliot said, their studies would result in radically different conclusions.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
For instance, many, including the then–Harvard University president Lawrence Summers, have used a 1970 study that showed men outperformed women 13 to one on the math portion of the SAT to explain why there aren’t more women at the top of stem fields. “People said brilliance in math is a male phenomenon,” Eliot said.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
Of course, it turned out women were being discouraged from pursuing STEM. Once more programs were put in place to foster this type of learning, the ratio dropped to three to one, Eliot said, and is now on its way to closing.

DETTE TEKSTSTYKKE ER IKKE ÆNDRET:
“We live in a gender-binary world,” said Eliot. “The default assumption is that these differences are hard-wired … But male and female brains are not much [more] different from each other than male or female hearts or kidneys.”