For a while now I’ve written the occasional post about claims that there are no evolved and genetically based differences between male and female behaviors, brains, or hormones. This claim is based not on science but on ideology, stemming from the fear that if you show differences between men and women in these respects, you will somehow justify a biologically based sexism: that women are inferior to men in some ways and thus can be treated as subordinates.
This “blank-slateism” has also been applied to differences between ethnic groups and is often used to dismiss the entire field of evolutionary psychology—for the same reasons. The ideological denialism of differences between any groups rests on the premise that difference equals inferiority and justifies unequal treatment and bigotry.
Well, leaving aside the possibility that genetically based trait differences may reveal better rather than worse performance of marginalized groups, the ideological dismissal of evolutionarily-based sex differences in brains and behavior is misguided. First, it’s based on the deeply problematic assumption that although differences between male and female bodies may well have evolved (most likely via some form of sexual selection), that cannot be true of the brain.
Yet there’s been equal time for divergent selection on both bodies and brains of males and females, so why did one (bodies) evolve sex differences and the other not (brains)? There’s no a priori reason to assume that brains are immune to divergent evolution, for sexual selection is based on female preference and male behavior, both of which presumably act through the brain. If bodily differences evolved by sexual selection, how can we rule out brain differences, especially those affecting sexual behavior? (The same holds if sexdifferences evolved by divergent natural selection.)
The answer to the ideological “sexes-must-be biologically-identical” argument is simple. We should, and must, give both sexes (and all ethnic groups) complete equality of opportunity as a moral principle—for such equality is the foundation of a good society. Average differences in behavior are just that—average differences—and do not justify differential treatment of individuals, whether their groups be based on sex or ethnicity. Somehow the “blank slaters” can’t grasp that simple principle.
To be fair, blank-slaters base their ideology on biological determinism being used in the past by bigots to suppress groups, but let us remember that blank-slateism remains not science but ideology, an ideology that is not only biologically misguided but whose fears can be overcome by changes in morality. And, indeed, changes in morality are overcoming it. Steve Pinker has documented the increasing moral equality of the sexes in his last two books.
Still, blank-slateism with respect to male and female brains persists, most prominently in the books of Cordelia Fine, an Australian philosopher and psychologist who has made a career out of debunking the idea that men and women are biologically different. I’ve now read both of her books on this topic, Delusions of Gender and Testosterone Rex, and found them a mixed bag. Fine is good at debunking bad research, as well as the implicit sexism of some researchers who work on brain biology, but is loath to admit, much less admire, the good research that’s shown differences in both brain anatomy and behavior between men and women. In other words, her books are not works of science but of tendentious ideology. (See here, here, here, and here for my posts on her claims.)
It is, in my view, a bit of a travesty—indicating the unscientific blank-slateism that has infected science—that Testosterone Rex won the Royal Society’s Insight Investment Book in 2017. At the time I called it “not a bad book, but a biased book. It’s not a judicious work of science, but a polemic.”
The same problems that plagued Fine’s books now appear to resurface in a new book by Gina Rippon that makes the same “no-difference-in-brains” claim: The Gendered Brain: The New Neuroscience that Shatters the Myth of the Female Brain, recently out in the UK and soon to be released in the US under the title Gender and Our Brains: How New Neuroscience Explodes the Myths of the Male and Female Minds. Wikipedia describes Rippon as “professor of cognitive neuroimaging at the Aston Brain Centre, Aston University, Birmingham.”
Despite ample evidence for genetically based differences in male vs. female brain structure and behavior, the reviews of The Gendered Brain and interviews with Rippon have characterized the book as doing exactly what its title says: aiming to dispel the myth that there are average differences between male and female brains. (Those differences, by the way, may be and probably are be effected through hormonal influences on that organ, which may not produce obvious morphological differences, even though there is substantial evidence for such differences.) The book has received extremely favorable reviews in Nature and The Guardian, though the claims and uncritical approbation in those reviews raised red flags for me.
The review/interview in the Guardian, for instance, characterizes Rippon’s thesis as indicting socialization as completely responsible for sex differences in behavior. The “plasticity” argument is one common to biological ideologues:
The next question was, what then is driving the differences in behaviour between girls and boys, men and women? Our “gendered world”, she says, shapes everything, from educational policy and social hierarchies to relationships, self-identity, wellbeing and mental health. If that sounds like a familiar 20th-century social conditioning argument, it is – except that it is now coupled with knowledge of the brain’s plasticity, which we have only been aware of in the past 30 years.
My suspicion that Rippon’s new book (which I’ll read when it comes out in the U.S) is guilty of the same sins committed by Cordelia Fine, is awakened by the following review in Quillette. It’s by Larry Cahill, identified as “a professor in the Department of Neurobiology and Behavior at the University of California, Irvine and an internationally recognized leader on the topic of sex influences on brain function.”
I’ll give a few quotes from Cahill’s review, quotes that could apply to Fine’s works as well. The first paragraph pulls no punches in enumerating the book’s problems:
A book like this is very difficult for someone knowledgeable about the field to review seriously. It is so chock-full of bias that one keeps wondering why one is bothering with it. Suffice to say it is replete with tactics that are now standard operating procedure for the anti-sex difference writers. The most important tactic is a comically biased, utterly non-representative view of the enormous literature of studies ranging from humans to single neurons. Other tactics include magnifying or inventing problems with disfavored studies, ignoring even fatal problems with favored studies, dismissing what powerful animal research reveals about mammalian brains, hiding uncomfortable facts in footnotes, pretending not to be denying biologically based sex-influences on the brain while doing everything possible to deny them, pretending to be in favor of understanding sex differences in medical contexts yet never offering a single specific research example why the issue is important for medicine, treating “brain plasticity” as a magic talisman with no limitations that can explain away sex differences, presenting a distorted view of the “stereotype” literature and what it really suggests, and resurrecting 19th century arguments almost no modern neuroscientist knows of, or cares about. Finally, use a catchy name to slander those who dare to be good scientists and investigate potential sex influences in their research despite the profound biases against the topic (“neurosexists!”). These tactics work quite well with those who know little or nothing about the neuroscience. Here are some lowlights. . .
The “lowlights” include praising bad studies claiming to show no average differences between male and female brains, and misrepresenting good studies that do show such differences.
Here’s Cahill’s summary of the known science and of the book.
So are female and male brains the same or different? We now know that the correct answer is “yes”: They are the same or similar on average in many respects, and they are different, a little to a lot, on average in many other respects. The neuroscience behind this conclusion is now remarkably robust, and not only won’t be going away, it will only grow.
The book is downright farcical when it comes to modern animal research, simply ignoring the vast majority of it. The enormous power of animal research, of course, is that it can establish sex influences in particular on mammalian brain function (such as sex differences in risk-taking, play behavior, and responses to social defeat as just three examples) that cannot be explained by human culture, (although they may well be influenced in humans by culture.) Rippon engages in what is effectively a denial of evolution, implying to her reader that we should ignore the profound implications of animal research (“Not those bloody monkeys again!”) when trying to understand sex influences on the human brain. She is right only if you believe evolution in humans stopped at the neck.
And everyone who isn’t a sexist or a racist, and is objective about the data, eventually arrives at this conclusion:
After almost 20 years of hearing the same invalid arguments (like Bill Murray in “Groundhog Day” waking up to the same song every day), I have come to see clearly that the real problem is a deeply ingrained, implicit, very powerful yet 100 percent false assumption that if women and men are to be considered “equal,” they have to be “the same.” Conversely, the argument goes, if neuroscience shows that women and men are not the same on average, then it somehow shows that they are not equal on average. Although this assumption is false, it still creates fear of sex differences in those operating on it. Ironically, forced sameness where two groups truly differ in some respect means forced inequality in that respect, exactly as we see in medicine today.
What he’s referring to is the neglect of women in clinical studies of medical interventions or drugs, which often show different outcomes in men and women. That’s based largely on biology rather than socialization, and shows differences between the sexes in bodies and their physiology. The best guess is that our brains will also show differences, and to deny that a priori as a possibility bespeaks a profoundly unscientific attitude.