Mick Connell is aware that he is reciting a stereotype. But, he says, the inescapable fact is that boys in their early teens simply do not see the point of English literature.

“In primary school, lots and lots of boys like reading lots and lots of things, just as girls do,” says Connell, who taught English and drama in the North of England for 13 years. “But, as they get into secondary school, the whole idea of dealing with literature instead of stories baffles them. They say, `Why are we spending hours poring over this? This isn’t real - it’s a story.’

“They’re much more interested in the practical mechanics of things. QED, cause and effect. There’s a sense in which they just don’t get the playing with language thing. I don’t know whether it’s innate, whether it’s learned or whether it’s taught. But they’re very, very keen on correctness, on the world starkly characterised. And girls aren’t.”

Assumptions about the differences between boys and girls pervade modern life, culture and education. The tropes are so familiar that they barely require repeating. Boys and girls learn differently. Boys are active learners; girls like sitting quietly. Boys are physically adventurous; girls are verbally dextrous. Boys like blacks and whites, rights and wrongs; girls are more analytical and thoughtful. Boys are good at physics and maths; girls are good at English and art. Almost everyone will know someone - teacher or parent - who has said: “I never believed there was a difference between boys and girls. But then I saw it for myself. I always treated them exactly the same and still they behave differently.”

And where people see trends, they want explanations. Scientists, psychologists and the opinion-holding masses have all stepped in to address whether such differences are the product of nature or nurture. Cognitive neuroscientist Simon Baron-Cohen is probably the most famous. Advocating the notion that there is a “male brain” and a “female brain”, he believes that neurological differences give men a more analytical view of life, while women have a more developed sense of empathy. So men are hard-wired to be better at reading maps, while women are programmed to be better at remembering a conversation.

But science, however mannishly cold and analytical it may purport to be, is a product of society. And society tends to believe that the dominant trends at any given moment are eternal and universal. Often, therefore, scientists are looking for reasons to explain pre-existing beliefs, rather than ways to question the beliefs themselves.

“A person studying their own culture is like a fish studying the water in their own goldfish bowl,” says Jo Paoletti, an associate professor at the University of Maryland in the US, who specialises in gender difference. “They’re so immersed in it, they can’t notice anything unusual in it.”

For example, a University of Pennsylvania study of 3,500 people between the ages of 8 and 22 found “pronounced” differences between girls and boys. The study, published in 2012, measured a range of psychological skills such as memory, reasoning and spatial awareness to see, once again, whether boys were better at map-reading and girls at empathising. Despite the academics’ claims, however, the differences between the sexes were in fact trivially small: of 26 possible comparisons, 11 areas showed no or negligible difference.

Give hard-wired the heave-ho

“The word `hard-wired’ ought to be expunged from people’s language,” says Anne Fausto-Sterling, professor of biology and gender studies at Brown University, in the US state of Rhode Island. “There’s no such thing as hard-wiring. If we were born hard-wired, then kids would be born walking and talking. Wiring develops - and by wiring, I mean interconnections in the brain.”

Such connections, she explains, grow as the newborn baby is stimulated. Those areas that are particularly stimulated grow particularly strong; those areas that lack stimulation remain undeveloped. This is why, for example, the extent to which parents talk to children during the first years of their lives hugely affects their level of literacy during the early years of school. The brain, like a muscle, requires exercise. And it is remarkably flexible: areas of strength and weakness can change and develop over time.

Fausto-Sterling has studied babies’ earliest speech and the ways in which their parents respond to this babbling. “You find that boys and girls are vocalising the same amount,” she says. “But mothers are responding much more to girls - babbling back at them. So they’re stimulating that part of the brain much more in girls than in boys.

“And mothers are picking up and moving boys physically a lot more than girls. When boys move, they’re praising their bodies a lot more: `My, how strong you are. What big muscles you have.’ With girls, it’s, `Oh, do you need help?’

“I’m sure, if you were to ask most mothers, they would say, `Well, I don’t treat my little girl any differently from my little boy.’ But the differences are statistically clear. And I think it has to do with very deeply embedded gender stereotypes.”

By the time children are 2 or 3, they are hearing words such as “boy”, “girl”, “he” and “she” and beginning to realise that these differences are significant.

“When you look at people, they vary in height, weight, attractiveness, hair colour, whether or not their earlobes are attached,” says Rebecca Bigler, professor of psychology at the University of Texas at Austin. “Kids are trying to work out what’s important, so they look for cues in the adult world. No one says, `Good job, left-handed person’, so kids think, that’s just a minor variation that I can ignore. But if a teacher says, `Good morning, boys and girls’, they realise boys and girls have got to be different.”

And young children, eagerly absorbing everything the world presents to them, pick up on these differences. But they do not entirely understand how they work. When Paoletti’s son was 3, he announced that he was going to be a mummy when he grew up. And then, when he was a little bit older, he would be a daddy.

“Children of 3, 4, 5 understand the terms `man’, `woman’, `boy’, `girl’,” Paoletti says. “But they don’t understand how they’re related. They haven’t learned a lot of biology yet. For them, what makes a girl a girl and a boy a boy are what they wear and what they play with. You see the fear that little girls have that, if they get their hair cut short, they’ll be a boy.

“But you’re also teaching them that being a girl or a boy is very important - that it’s essential to what they are. So there’s an urgency to maintaining that. A little girl who arrives in a pink world learns that this is home, that this is comfortable. She develops associations with pink that seem natural and innate but are really taught.”

Picking up on this urgency, three- and four-year-old children begin to enforce gender conformity with dictatorial zeal. The fear is that any child who strays from within the neatly drawn gender outlines - one with a skirt, the other without - runs the risk of sex slippage. Boys will tell classmates that they can’t wear pink because it is “a girl’s colour”, or that they can’t check “a girl’s book” out of the library. Girls, meanwhile, will tell each other that they cannot play football “because you’re not a boy”.

“They’re preventing other boys and girls from straying into dangerous territory,” Paoletti says. “They’re looking out for them.”

Philippa Seago has seen this in action. She was recently informed by her five-year-old son that one of the differences between boys and girls was that girls could not be astronauts. Her son’s Reception class had been learning about outer space, and teachers had bought a toy rocket for children to play with. But all the astronaut toys that came with the rocket were men. “Obviously the school buys what’s available,” says Seago, a teacher herself. “But my son sees that, and he’s going around trying to make sense of the world and put things in boxes. And this is what he’s getting from school.”

`What a good blonde you are’

In fact, school plays a key role in reinforcing gender differences, according to Bigler. “If every morning the teachers said, `Good morning, blondes and brunettes’, or `What a good blonde you are, putting down your pencil when I asked you to’, kids would really pay attention to hair colour,” she says. “And if the teacher said, `Good morning, white kids and black kids’, what do you think would happen in the playground, even if you never said anything bad about black people?

“Kids tend to think, `If you’re labelling me a boy a hundred times a day, it must be important. It must make a difference. Otherwise why would you be doing it?’”

This, too, is something that Seago has witnessed. The textiles teacher at the school where she works in Derby, in England’s Midlands, keeps forgetting that she has a boy in her A-level class. “Right my girls,” she will say to her students. “Today we’re going to do.” And then she catches herself. “Right, girls and boy.”

This is the first year that a boy has studied A-level textiles at Littleover Community School. “From the girls’ point of view it’s quite amusing when she says `my girls’,” Seago says. “But from the boy’s point of view I think it’s a bit uncomfortable. It’s really quite a statement. It sets out that he’s unusual. If you make a child feel different, I don’t think that’s a good thing.”

Seago began, therefore, to think about unconscious biases in her own teaching. She had long used a boy-girl, boy-girl seating plan, which allowed her to place loud, potentially disruptive boys next to quiet, well-behaved girls. “I shouldn’t do that,” she says. “I’m putting a naughty boy next to a good girl in the hope that she’ll care for him and help him with the work. But it’s not the quiet girl’s responsibility to make the boy learn.

“When I have a rowdy girl, I don’t think of them in the same terms, necessarily. I wouldn’t think, `That boy will look after her’. I’d probably think, `He can be a spacer between her and the next loud girl’.”

Connell, meanwhile, began to notice that his students defied gender stereotypes as often as they confirmed them. “Whenever I asked for data on school library use, the group that used the library most often in their own time was the boys, by a mile,” he says. “Part of that is that it’s a haven away from the horrors of the playground. But if you look at the names of student librarians, it would be a big, long list of boys again. I just don’t believe that those boys are all sitting there with The Guinness Book of Records.”

He has other examples, too: the large numbers of girls whose favourite subjects are drama, computing or physical education; the many boys who, once they have learned to understand the point of literature, embrace poetry and fiction. “By the time they get to 14, 15, boys’ expressive writing is just as risky and daring as girls’ is,” Connell says. One boy, for example, wrote about the abuse his mother had received at the hands of his drunken father. Another wrote about caring for his diabetic mother. “There are some remarkable examples, dealing with really sensitive issues of disclosure and emotions.”

Bigler agrees that gender lines are far from clear-cut. “It’s easier to label boys and girls, rather than individual variation,” she says. “Are there some girls who would like to hold hands and sit in a pink classroom and whisper sweetly to each other? Yes. Are there some who would hate it? Yes.

“There are plenty of sedentary boys and active girls. But we already know that: there are high-activity people and low-activity people. It’s just not sexy to say that some individuals have trouble sitting still for long periods. It’s sexier to say, `Boys are like this and girls are like this’. It fits in with our society.”

And the more society looks for evidence to prove that boys and girls are different, the more publicity these purported differences receive. This then reinforces the stereotypes, inspiring more theorists to attribute them to hard-wiring.

“There’s a danger that, if you’re expecting boys to be better than girls at maths, you’ll give them harder questions,” Seago says. “Or you’ll let girls get away with not knowing the answer. But if you’re not challenging, for example, a girl who’s good at physics, she’s probably going to be quite bored in the lessons. Then she’s not going to take it for A-level, because she finds it boring.” Seago now makes a point of calling on students to answer questions by picking a name at random from a pot.

It takes all sorts

But children respond to what they see, too. No matter how many times students are told that no subject is out of bounds for them, it still might not counter the message given by a physics department full of men or an English department full of women. This message can sometimes be compounded by exactly those measures intended to obliterate it. Give students a supposedly boy-friendly English curriculum consisting of Macbeth, Of Mice and Men and war poetry and they will only encounter two women in their reading - one a murderer and the other referred to simply as “Curley’s wife”. “It’s a pretty odd version of the world,” Connell says. “It’s very sad.”

Seago has taken deliberate steps to make her own classroom more gender-neutral. As well as re-examining her seating plan and the ways in which she chooses students to answer questions, she has made a conscious effort to be aware of the language she uses. “It just feels wrong to refer to the men doing this and the girls doing that,” she says. Then she pauses. “Well, it is wrong.”

Bigler, meanwhile, advocates highlighting children’s similarities as well as their differences. Instead of asking boys and girls to line up, for example, a primary teacher could suggest that those who like spaghetti line up, or those with freckles. “What you teach is this wide array of human variation,” she says. “Even though you may not be like this person in some ways, we all have bonds with each other. Yeah, she might be a girl, but that just tells you she pees sitting down. It doesn’t tell you how active she is or what subjects she likes.”

And, above all, teachers should remember that social difference is learned and can therefore also be unlearned. “Children are socialised into adapting different interests and abilities by cultural stereotypes,” Bigler says. “Then, when someone comes along and says, `In fact, boys and girls are so different that their brains are different and they learn differently’, we’re prepared to believe them.

“It’s easier to say that some people are born like this than to explain how stereotypes develop. That’s a damn complicated story.”