My four year old daughter, like many girls of her age, has become obsessed by all things pink. Why? It's in her genes, says neuroscientist Anya Hurlbert. In August, virtually every newspaper splashed Hurlbert's latest research that showed, would you believe it, that women like pink and men prefer blue. Back in our hunter gatherer days, Hurlbert speculated, 'women were the primary gatherers and would have benefited from an ability to home in on ripe, red fruits'. Stone Age men, on the other hand, 'would have a natural preference for a clear blue sky because it signalled good weather'.
There is only one problem with this argument. A hundred years ago boys liked pink, girls preferred blue. As the Ladies Home Journal put it in 1918, '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'.
It is not difficult to mock the argument that men and women wear pink and blue genes. Yet this is only the more absurd form of claims about gender differences that most people accept as self-evident. We all know, for instance, that women are better communicators than men. They talk more. They talk about people and relationships where men tend to talk only about facts and things. And they try to be inclusive and cooperative rather than competitive and assertive.
Think again, says Deborah Cameron, professor of language and communication at the University of Oxford. Her new book unpicks what she calls 'the Myth of Mars and Venus'. The myth began as the whimsical title of a best-selling self-help book - John Gray's Men are from Mars, Women are from Venus. Fifteen years on, the metaphor has mutated to scientific fact. Psychologists now routinely talk of the 'male brain' and the 'female brain' and about men and women being akin to different species.
Such stark distinctions, however, are belied by the facts. There are clearly anatomical differences between the brains of men and women, differences that have evolutionary roots. Yet, careful analysis of all the research on gender differences on tasks such as vocabulary, verbal reasoning, and assertiveness of speech reveals mostly small or non-existent differences. It also shows that the best predictor of the kind of language someone might use is not their gender but their social role. Where men are in jobs that involve facilitating others - such as teaching or broadcasting - they use stereotypically 'female' forms of speech. Where women find themselves in positions of authority - as in politics or business - they are assertive and competitive, contrary to the popular myth that women bring a uniquely feminine touch to management and public debate.
The crucial distinction, Cameron suggests, is not so much that between men and women as that between the public and private realms. The public sphere often requires assertive, competitive language. Because this sphere has historically been the province of men, so such language has been associated with maleness. In the private sphere, relationships, emotions and feelings become more important. And these are seen as female linguistic attributes because of the association of women and domesticity.
Could it not be that men dominate the public sphere because they are naturally assertive and women the private sphere because they are better at handling intimacy? Unlikely, suggests Cameron, as the same individual can switch between different kinds of talk depending on what is required of him or her.
The debate, Cameron insists, is not one between nature and nurture. While evolutionary psychologists see the roots of gender differences in evolutionary history, others, especially self-help gurus, see the distinction as cultural. 'The biological determinist and the cultural relativist', Cameron writes, 'may travel by different routes, but they arrive at the same destination.' A key problem, is that 'we actively look for differences, and seek out sources which discuss them' but 'are much less attentive to, and less interested in hearing about, similarities between men and women'. This inevitably biases both research and the interpretations of data.
As for my daughter, she is obsessed not just with all things pink, but also with dinosaurs, racing cars and space travel. When she grows up she wants to be an astronaut with a pink rocket. Children do not come neatly packaged in black and white, pink and blue, Mars and Venus. Nor does the world.