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Michael Joseph, pp 228, Pounds sterling 12.95 Lynda Birke

N THE 1870s one Alabama doctor claimed: ‘Beware! Science pronounces
that the woman who studies is lost,’ in response to feminist agitation for
higher education. So, too, science can provide the antidote to more recent
demands for women’s emancipation; if male dominance is all nature’s fault,
then patriarchy is inevitable and feminists misguided.

BrainSex is in this genre. Like its predecessors, it asserts that science
has clearly shown differences in the way that men’s and women’s brains function;
these, moreover, determine differences in behaviour and intellectual ability.
If we remain unaware of this all-encompassing dictate of our biology, then
that is due to the power of prevailing beliefs in ‘cultural conditioning’.
The sexes are not the same; to believe otherwise is to ‘build a society
based on a biological and scientific lie’.

Anne Moir and David Jessel claim that men’s and women’s brains are ‘wired’
differently as a result of exposure to different levels of sex hormones
before birth. This wiring ensures that their brains work along different
lines from the moment they are born; so, for example, girlsacquire verbal
skills morequickly, and boys develop greater spatial ability. The result,
Moir and Jessel suggest, is that boys excel in maths and science, while
girls are more concerned with communicating with other people.

As adults, male brains ensure that their owners singlemindedly pursue
careers. ‘It is men,’ say Moir and Jessel, ‘who feel driven to discover
the secret clockwork of Creation itself, the laws of physics, motion (or)
gravity.’ The drive stems from greater amounts of testosterone, the ‘aggression
and dominance hormone’. Hormones, meanwhile, induce females to become maternal;
and they ensure that women are naturally ‘fastidious’ and so more suited
to domestic work, like stacking the dishwasher.

Hyperbole is an obvious risk of popular accounts of science. Thus, ‘virtually
every’ neuroscientist believes that fetal brains are ‘awash’ with hormones,
exerting a powerful ‘prenatal mind control’. ‘Literally hundreds of studies’
show sex differences in spatial ability. The rising ‘hormonal sap of puberty’
helps to continue the differences into adulthood.

That is heady stuff. Science as incontrovertible truth is a powerful
idea, and one often invoked in response to woolly sociological notions that
we might work to change society. But what has science had to say about brains
and sex? Prenatal hormones do seem to influence how some parts of the brain
develop. One small area of the hypothalamus, for example, appears to be
larger and to have more connections between nerve cells in male mammals
than in females. But this is not too surprising: one job the hypothalamus
does is to organise the body’s production of sex hormones. In females, this
is cyclic, while in males it is not. Unambiguous evidence of structural
differences in the rest of the brain, however, is scant.

Researchers have not suppressed the evidence that does exist: on the
contrary, the discovery of differences in the hypothalamus received extensive
media coverage at the time. But one reason why it has not received more
accolades is that many scientists are more cautious in extrapolating from
cells to human society.

Not only are some scientists more cautious; several have also pointed
to the methodological difficulties that inevitably beset studies of human
development. It is rarely possible to control variables, such as the behaviour
of parents towards children, for example. And if some – not ‘literally hundreds’
– studies show that males tend to outscorefemales on tests of spatial ability,
how can we unravel the many cultural influences at work? Meccano sets have
a lot to answer for.

The cause of scientific truth is not helped by reducing the complexities
of human development to chemical cocktails. Hyperbole allows that cause
to slip even further away. Congenital adrenal hyperplasia (CAH), for instance,
is a condition in which the adrenal glands, situated adjacent to the kidneys,
secrete excessive levels of particular hormones during early development.
But even popular accounts of science should not refer to CAH as an abnormality
of ‘the kidneys’. Nor do ‘we know how to make homosexual rats and monkeys’;
what ‘we’ can do with hormones, rather, is to alter the frequency of certain
patterns of behaviour, such as mounting. That does not createa homosexual,
be it rat or anything else.

Explanations of sex differences that uphold the status quoare familiar
enough. The biastowards accounting for only some observed differences, such
as male predominance in science, is familiar, too. I doubt if dressmaking,
for example, could be accomplished without spatial skills, yet that is stereotypically
the preserve of women.

What is less familiar is the alleged extreme environmentalism against
which Moir and Jessel argue. Few indeed are the liberals, feminists or woolly
sociologists who would attribute all gender divisions solely to ‘cultural
conditioning’ onto the ‘blank slate’ of infancy. Among the other factors
they might consider are social class and power. Loss of money, suggest Moir
and Jessel, presents a terrible threat to the (hormonally based) masculine
self: stockbrokers might even jump out of Wall Street skyscrapers. And so,
of course, might a woman living below the poverty line, struggling to raise
a family on what is left of child benefit. She may not even know how to
stack a dishwasher.

We should, Moir and Jessel urge, abandon the pursuit of equal opportunities;
rather, we should celebrate difference. I must admit that I was not aware
that feminists, liberals and so forth had even denied difference: what they
have said, rather, is that difference should have nothing to do with equality
and human rights.

‘Liberal’ educators would agree with one claim, that tailoring science
teaching to girls’ experience and needs is desirable. But I doubt if they
would agree with many of the other suggestions. Affirmative action, for
example, they imply willmean inefficiency, with lesscompetent women in positionsof
responsibility. ‘Would you,’ they ask, ‘let your children fly on an affirmative
action airline?’

I must confess that I did not try the quiz: ‘What sex is your brain?’
As a woman scientist who hates housework, I think I can guess the result.

Lynda Birke is a biologist and science writer.