Neuromyths and Neurosexism
May 18, 2009
SEARCHING OUT DIFFERENCE – neuromyths and neurosexism
Anarchist communists believe in an egalitarian society, where people are no longer judged on differences in ability and are no more or less entitled to the benefits from our collective society. As long as it is not used to discriminate, we just don’t see difference as a problem. But could this make us insensitive to scientific claims about the discovery of innate differences between men and women, or do these claims need to be better understood, and challenged by non-experts?
Over the last couple of decades, intense interest in brain research, including the 1990s ‘Decade of the Brain’, has helped bring together many different fields of scientific enquiry, especially biology with psychology. From biology, the physical structure of animal and human brains and their electrical and chemical processes are better understood than ever. Computer imaging like MRI scans, as used in medicine, are being applied to find out how brains change when people perform basic tasks with words or pictures. Animal and human behaviours, and theories of the mind from psychology, can now be put to the test by looking for variations in chemistry, electrical activity or blood flow in the brain. Some of these experiments have been directed at searching for differences between the sexes and factors that might be related to sexuality. Where differences have been detected, it is tempting to feel that we are nearer the truth than ever.
On the other hand, we know that scientific enquiry can so easily be used to back up prejudice. In the 19th century almost all scientists believed that people of colour and women were intellectually inferior to men and this just needed proving. An experiment with brain size by anthropologist and craniologist Paul Broca, performed by filling up skulls with seeds and measuring the difference in volume, would do nicely. Since the female brains were on average 10% lighter that the males’, this proved a lack of the region of the brain where the intellect was located! Most notoriously, in 1879 Gustav Le Bon used these results to compare the brain size of women unfavourably with those of gorillas, children and “savages”, using this as good reason why women should not be educated. By 1909, it was clear that brain size was really just a reflection of body size. Never mind that any connection between brain size and intellect is a fantasy. Never mind that even the figure of 10% from original data is questionable due to age, disease, and other effects on body growth not being controlled (most of the women in the original experiments were older than the men, and brains can shrink with age-related degenerative diseases). Apart from size, supposed differences in the number of folds on the surface of one part of the brain showed women’s inferiority; then, in 1909, it was shown that there was no difference. The story goes on and on, with differences in variability of brains being used to show male superiority – men were less “average” than women, an idea that carried over into the IQ tests of the 1970s. A similar story from the 19th century can be told about the linking of left-handedness to criminality, and incidentally, the possibility of brain abnormality causing criminal behaviour was investigated only as long ago as 1997 to try and explain Ulrike Meinhoff’s ‘slide into terror’ as a member of Red Army Faction – her brain had been preserved for 26 years, then given to a neurologist!
Over many decades, genetics has provided insight into sex differences at a molecular level. Before discovery of DNA, it was already understood that certain diseases are inherited differently by male and female children. This is described in terms of passing on chromosomes, DNA sections of a person’s entire genome that are present in cells of the body. Most cells have all the chromosomes, but sperm and eggs have only one of either sex chromosome, X or Y. When the egg and sperm come together, the foetus’ cells become either XX (female) or XY (male). This is not always the case, though, and some people have XXY, XXXY, XYY, although having a Y is usually necessary to give you balls, so to speak (apart from the rare ‘XX male’ condition where the relevant SRY gene from Y jumps to the X). It becomes more complex still. Hormones are involved with a chain of events that activates a male baby’s SRY gene and results in him growing testes. Some of the same hormones, and others, are involved continually after birth. These levels of so-called male and female sex hormones in the body are not static over time or age. For example, testosterone is thought of as the male hormone, but many women have higher levels than men. Levels change over a woman’s menstrual cycle and with age. Coming sexually aroused makes hormone levels go up temporarily, and so on. A lot more is now known about how the brain takes part in processes involving hormones. For example, some receptors in the brain respond to hormones from other parts of the body. Interestingly, most testosterone has to be converted to oestrogen (a so-called female sex hormone) before it is received by the brain, so the actual effect of hormones on the brain is very similar in men and women.
With all this knowledge, it would be nice to think things have changed in the 21st century from the days of Gustav Le Bon, but it seems that sexism is alive and kicking, and we can now talk reasonably about neurosexism. Books entitled ‘The Female Brain’ and ideas of left-brain versus right-brain types of people are now part of popular culture. They use a mixture of science and myth to explain why women don’t get so bored when ironing, why working women inevitably get confused juggling work and home life, can’t fly planes safely and so on. Many of these ideas have some origin in scientific experiments which attempt to measure hormone or brain activity levels. When a difference is found, explanations about innate, ‘hard-wired’ behaviours are usually offered. More ludicrously, origins of these behaviours within our evolutionary past are explained using theories about the way early ‘hunter gatherer’ societies could have been structured. For example, you obviously need a different brain to go hunting, an unpredictable activity, than to find nuts and grubs, or stay at home cleaning the cave, don’t you? These kinds of stories are woven from studies of “primitive” tribes living now, since the fossil record tells us so little. One brilliant example of the kind of madness coming out of the field of ‘evolutionary psychology’ is a study claiming to explain why girls prefer pink, since prehistoric gathering required identifying pink berries, apparently. Never mind that the study on 21st century twenty-somethings only asked about preference and not ability to distinguish colours, you only have to go back to 1914-18 to find magazines saying things like: “There has been a great diversity of opinion on the subject, but the generally accepted rule is pink for the boy and blue for the girl. The reason is that pink being a more decided and stronger color is more suitable for the boy, while blue, which is more delicate and dainty, is prettier for the girl.” (Ladies Home Journal, 1918). Pink for girls came in the 1940s. Oops, so much for the prehistoric berry theory then.
For another example of neurosexism, let’s look at the idea of spatial awareness differences between genders, arising from psychology experiments where people sit down to look at and compare shapes, or locate objects on a page. Rats running around and getting lost in mazes have also been studied. These experiments have arguably shown some differences between sexes, and it is from these that popular books back up their just-so stories, like why women can’t read maps or park cars as well as men. Still, a difference is a difference, right? Not quite. Aside from the possibility of different life-experiences, what was once thought of as better general spatial awareness in men is now known to be much more complicated. With further research, on average, women seem to be better at some spatial tests than men and vice versa. So, was it that the definition of “spatial” was not well enough defined, or is there not really so much difference? The goal posts move yet again. Neuroscientists also claim that there are different “thinking styles” in men and women, or in homosexual and heterosexual people.
Now bring in the hormone levels and MRI scans. People doing spatial or other cognitive tests (visual, audio or language tasks) have hormone levels measured in their blood, saliva or urine. Can a difference in hormone level be related to their ability to perform the task? Bizarrely, in some tests men with higher hormone levels do worse than other men, but women with higher than average hormone levels do better! So is there really a causal link between hormones and spatial test results, or was is just due to individuals having spent more playing with lego as children? As with hormone levels, studies with MRI scans claim to have shown differences between men and women in the way particular volumes of the brain have greater or less blood flow when doing a task. Recently, though, it seems that many of these differences go away when the experiments are done properly. In spite of early experiments to the contrary, MRI now provides evidence against both localisation (psychological events relating only to defined locations in the brain), and lateralisation (psychological events relating mainly to only one side of the brain). This of course puts, or should put, into question previous experiments that purport to show innate and permanent differences between men and women. Unfortunately, these neuromyths are hanging on so strongly and are now so pervasive in society that educationalists are starting to worry that learning in schools will be affected by this assumed knowledge with little scientific basis.
One example of how things can come unstuck was a study of gender identity in girls with a condition called adrenal hyperplasia, who have masculinised genitals. Data came from asking their mothers about behaviour that was compared to a sister without the condition. Results of one study showed evidence of increased energetic play, or “romping”, which is normally attributed to boys. Quite apart from the possibility of mothers treating sisters differently, or typecasting gender behaviours, the killer blow came in a later study comparing children with adrenal hyperplasia and those with diabetes. Both groups were found to exhibit the energetic behaviour, suggesting that childhood illness in general was the common factor, nothing to do with gender identity. But without this last study to show otherwise, how many of us would continue to believe the gender identity theory?
So, as revolutionaries, we have to be careful not to fall into the neuromyth trap. The assumed “facts” about difference gleaned from scientific experiments have to be understood in greater depth and broken down before taking any media headline even slightly seriously. Was the experiment just a psychology experiment asking a bunch of student volunteers to look at pictures, or did it involve some measurement of hormones or brain activity? How was the hormone level measured, and was menstrual cycle taken into account? Was the experiment done on rats where the results may or may not apply to humans? Could the results have an environmental origin, as in the example above? Does a scientist doing a psychology experiment really have the expertise to make claims about hormone levels or judge theories about prehistoric society, or are they making connections that are just not there, based on prejudice? Do they perhaps want it to be true, like Simon Le Vay who hoped his (flawed) experiments showing brain differences between homo- and heterosexuals could help lesbian and gay men become more accepted? Are they even a racist like James Watson, one of the co-discoverers of DNA who got a Nobel prize? (Rosalind Franklin, the woman on the research team, didn’t, by the way!) This is not to say it’s easy to get to the bottom of media headlines about gay-genes or female brains, especially as the details of the experiments are buried in scientific journals that you have to pay for unless you study or work in a university.
Finally, here are two things that often get left out of discussions about innate abilities or behaviour. Firstly, we know that it is possible to change our ability by practising a task or change behaviour by learning to think differently. It may take a few hours or days or years, but we know we get better over time when we practise something, the opposite if we don’t. One practised individual can easily overcome small differences in averages between experimental groups of men/women or gay/straight (assuming these differences exist at all). So to a great extent we can just choose what to become good at, given the opportunity. Secondly, in spite of inequality in upbringing, education and diet, cultural diversity, and discrimination due to racism, sexism and homophobia, the amazing thing about human beings is the overriding similarity in so many of our abilities and capabilities. How much more will this be so when inequalities are removed as they would be in an anarchist communist society?
The main sources for this article were:
• Steven Gould, The Mismeasure of Man, 1996.
• Lesley Roberts, Sexing the Brain, 1999.
• Steven Rose, The 21st-Century Brain, 2005.
• John Hall, Neuroscience and education – what can brain science contribute to teaching and learning?, 2005.
• Betta Schnitzel, Gender and ethically relevant issues of visualizations in the life sciences, 2006.
• Ben Goldacre (Bad Science blog), Pink pink pink pink pink moan, 2007.
• Greg Downey (Neuroanthropology blog), Neurosexism, size dimorphism and not-so-‘hard-wiring’, 2008.