If you cut my head in half, out would spill sugar and spice and all things nice, obviously. The part of the brain that does parking would be small, but the part that organises cupcakes and friendship would fizz like sparkling rose. Because I am a girl whose mushy head is "hardwired" for girly things.

As ever, when I see the latest stuff on gender differences in the brain, I feel that I am barely female. Some parts of my brain have gone rogue. But before anyone gets out a soldering iron to rewire me, let's um … think about it.

What we are told is that neuroscience is actually a mass of disciplines: neurology, physiology, psychology, molecular biology and genetics, all of them ramped up by new ways of imaging the brain. Neuroscience has to be social, as we are social animals, and yet it stumbles over "a theory of mind". Are we simply a collection of brain processes that we experience as thoughts and feelings? If we are going to locate these inside the brain, we need some philosophical models too. It is all pretty epiphenomenal for my fluffy little brain. Which is smaller than most men's.

My brain also lives in a female body and clearly there are differences between men and women. But the latest overhyped study, which suggested that – guess what? – men are good at structure and co-ordinated action (map-reading?) and female brains are designed to facilitate communication (everything else?), is about as plausible as the finding reported in one notorious Daily Mail story that women were programmed by evolution to be "bitchy". This was based on showing 46 women in Canada pictures of other women in tight T-shirts. If this is science, I am Richard Dawkins.

Neuroscience is just as useful as evolutionary biology when it comes to reinforcing stereotypes in a pop-psychology manner. Are you right-brained (creative, intuitive) or left-brained (organised, systematic)? Do a quick quiz to see, rather than understand that this dichotomy has been fairly comprehensively debunked. The interaction between the hemispheres is what counts, but this is less marketable stuff. Such personality tests are sold to anxious parents, used in business recruitment and targeted at schools. All of them confirm what we already know, not what we could know.

The great insights now are around the plasticity of the brain, how new pathways can be formed even after damage, and how they are formed through experience. Yet there is a focus on imagery and which bits of the brain light up, because it is whizzy and fun. Spending a lot of time a while back with neurosurgeons after a close relative suffered a head injury taught me that brain scans are still blunt intruments, that we don't know sometimes if some functions can be taken over by other areas of the brain, if nerves can repair. It taught me that coma is still a mysterious state from which one does not wake up, but rather swims slowly to the surface. All these very clever doctors were more than happy to talk about what they did not know about the brain.

Now, though, neuroscience has achieved a quasi-religious status. There are, of course, drug companies waiting to improve our mental states; the military is also heavily invested in some of the research, as are those who think we will soon be able to predict "criminality" and lock people up before they do anything. Right now, we have politicians basically telling us that intelligence is innate and inequality therefore predetermined. There are, of course, many brilliant scientists who are appalled at this.

Cordelia Fine, for instance, is wonderful at debunking the neuroscience of sex differences, which began in the mid-19th century. These differences were used to argue against giving women the vote. Now they are being used to confirm that women are empathetic, but not power hungry or good at maths. Something as complicated as language does not live in one part of the brain, whether that language is poetry or maths. What Fine dubs "neurosexism" explains female inferiority, lower pay and the lack of women in public life. Is this inferiority located in individual brains or in culture?

Indeed, the latest debate on education shows that we absolutely need a combination of creativity and analytical skills; the binary of left/right brain thinking is inadequate. Of course we can find studies that reinforce gender stereotypes and use a determinist model of the brain. All kinds of self-help books are flogged on the back of this.

How hormones change brain organisation has yet to be fully explained. Many people feel neither male nor female. We see more autism in men, more Alzheimer's in women – and all of this is to be explored. But the idea of plasticity, the ability to change our ways of thinking, gets lost in the new neuro-mythology, which, as authors Hilary Rose and Steven Rose have argued, ignores the ways in which "culture and education shape neuro-cognitive function".

The truth is our brains are much more similar than they are different. That's not a headline you will ever read, is it? "Men and women: much the same!"

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