"Do men and women have similar abilities, desires and needs?" is a question all of us must address. A parent dealing with a girl's craving for dolls and a son's obsession with war games, a teacher managing boys' boisterousness and girls' diffidence, a couple negotiating childcare and housework and a CEO assessing fair practice in policy and promotion are all likely to conclude that their best efforts to achieve gender equality are scuppered by essential differences. In Delusions of Gender the psychologist Cordelia Fine exposes the bad science, the ridiculous arguments and the persistent biases that blind us to the ways we ourselves enforce the gender stereotypes we think we are trying to overcome.

If we think we have left behind the cliché "Men think and women feel", Fine persuades us to think again. Newer, shinier versions take hold every year: "The female brain is predominantly hard-wired for empathy. The male brain is predominantly hard-wired for understanding and building systems," writes Professor Simon Baron-Cohen, while the neuroscientist Louann Brizendine describes a "female brain" and a "male brain" forever divided by their genetic destinies. Drawing on more sound but less high-profile research, Fine argues that most gender differences arise within social, cultural and personal environments that influence what hormones we produce and how our genes work.

The human brain, female and male, has a remarkable plasticity. To assume that many complex adult traits are determined at birth is "so last century". Genes only lead to traits through interaction with environment. Yes, even the incontrovertibly genetic trait of having male or female genitals is environment-dependent: the foetus's male genes trigger the production of male hormones by the mother and the bathing of the foetus in those hormones is what leads to male genitals. Outside the womb, social environments continue to shape our brains.

Young children work hard to figure out the codes for "boy or girl" – the first category they are subjected to in our society. They quickly graduate from being gender detectives to gender enforcement agents. In very early childhood boys are at greater risk of jeer pressure if they stray across gender lines; it takes far more courage for a boy to be a "sissy" than it takes for a girl to become an adventurer or even a bully. Later in childhood, however, any spotlight on gender is more likely to put a freeze on girls' abilities. When school-age children are told that they are being given a test to see how good they would be at mechanics, the girls do less well on the same test than they do if they are told they are being given a test to see how good they would be at sewing. The girl does not opt to take the primarily male physics course, and hence is far less likely to develop the skills that, incrementally, lead to a successful science career. The cultural emphasis on female physique undermines the ability to concentrate on other things: when instructed to complete a short maths exercise while wearing either a bathing suit or a sweater, women wearing a bathing suit performed less well than the women wearing a sweater, but the men's performance was unaffected. These men and women, as parents, may perpetuate the myth that her hormones make her the better carer, but research shows that his hormones are equally affected when he holds the baby.

Most studies about people's ways of thinking and behaving find no differences between men and women, but these fail to spark the interest of publishers and languish in the file drawer. The oversimplified models of gender and genes that then prevail allow gender culture to be passed down from generation to generation, as though it were all in the genes. Gender, however, is in the mind, fixed in place by the way we store information.

Mental schema organise complex experiences into types of things so that we can process data efficiently, allowing us, for example, to recognise something as a chair without having to notice every detail. This efficiency comes at a cost, because when we automatically categorise experience we fail to question our assumptions. Fine draws together research that shows people who pride themselves on their lack of bias persist in making stereotypical associations just below the threshold of consciousness.

Everyone works together to re-inforce social and cultural environments that soft-wire the circuits of the brain as male or female, so that we have no idea what men and women might become if we were truly free from bias.

Perhaps Fine is too intent on referencing every argument to move beyond the data, but it is regrettable that she does not go further. Among our wonderful genetic gifts is the ability to change our environment so that our genetic inheritance can be expressed in unprecedented ways. The eagerness and recklessness with which we devour theories about gender suggest a hungry imagination, waiting to feed on ideas of real substance. Fine has shown how we distort and impoverish the world we are trying to understand, but not how to use our intelligence to produce new environments, with better outcomes.

Terri Apter's What Do You Want from Me?: Learning to Get Along with In-Laws is published by WW Norton.