But how do children themselves explain the difference in achievement?
My survey of 134 London school children gave 26 possible reasons for the sexual imbalance and asked whether pupils agreed or disagreed. The responses revealed high levels of confidence among the girls, with more than 30 per cent believing they were simply more intelligent than boys. Perhaps more surprisingly, almost 20 per cent of the boys agreed with them.
Most respondents, though, rejected the biologically determinist view and offered some more interesting insights into the likely causes of the gender gap, although none blamed the lack of job prospects.
The Year 9 children came from a racially and socially mixed co-ed comprehensive on the HackneyIslington borders in north London. It is a popular school with a substantial waiting list and improving GCSE results above the average for inner London (although below the national average). Local parents are particularly keen to get their boys in but often send their daughters to one of the local girls' schools. As a result the school population is two-thirds male. But even with this imbalance, the girls do better than the boys.
Girls' and boys' responses were analysed separately, but the only substantial area of difference was over the question of favouritism. Almost seven out of 10 boys believed teachers favoured girls. But the girls were equally convinced teachers showed them no favours. Many also said boys' bad behaviour attracted all the attention. One of the girls said if the teachers did seem to favour girls it was because "they like talking to people who work and behave - and that is mainly the girls".
It was a well-made point. Some of the boys seemed to regard working and behaving as acts of treachery. Indeed, some boys seemed to believe the girls deliberately "sucked up" to distract teacher attention. As one put it: "We just want help and to be the same as girls. How can we do that if the girls are just sucking up to the teachers?" The boy who made this plea was at least twice ejected from the room for being noisy and disruptive, and seemed to live in a permanent state of rage about the unfairness of life.
But he was one of the more articulate exponents of a school of thought that sees teachers as unreasonable tyrants and pupils, particularly boys, as a put-upon minority, with girls acting as a kind of fifth column undermining their struggle.
This difference in the way boys and girls view the school, themselves and their relationship to the authority structure is a significant factor in the educational gender gap, with a possible clue to the difference to be found in the ways in which boys understand what it means to be male.
Back in 1978, when Paul Willis wrote Learning to Labour, he described how boys constructed alternative authority structures and policed them. He claimed that rejecting the expectations of peers required a strength of purpose few adolescents possessed. So if hard work is seen as a sign of weakness and being pleasant to teachers as effeminate, it is vital for a boy's standing in the group to avoid being seen to co-operate or work hard.
Willis saw anti-intellectualism as a characteristic of working class male sub-cultures and concluded that the boys were undermining their own educational chances by mimicking, in school, the anti-authority, anti-intellectual ethos of the factory floor, in which working class men banded together to counter the power of the boss.
In Black Masculinities and Schooling (Trentham Books, 1997), Tony Sewell described a similar situation among young black men but, instead of class resistance, he read it as black resistance. Unlike Willis, Sewell looked (in passing) at the girls as well and found that, although they too held themselves aloof from the school authority system, they didn't do it at the expense of their education. The difference in responses to authority clearly had more to do with gender than race.
At the same time, Sally Powell and her colleagues from the University of Bristol had been looking at the academic performance of high-achieving children over their school career ("Gender identification and academic achievement", International Journal of Inclusive Education, Vol 2, No 2). They found the same form of resistance among boys in elite grammar schools.As one boy put it: "You were supposed to make it look easy, and never get caught working."
Girls at the London school had no recourse to extensive studies, merely their own powers of observation. But three in four of them agreed boys under-achieved because they were "too busy showing off and trying to look cool". One of the girls later wrote: "Power games play a big part in boys' lives. There is normally one boy who has most control, although he can't operate without his friends or, as he sees it, 'his followers'. They rely on one another more than they like to admit and possibly realise. This is because they want to prove they can be independent and headstrong and they don't need anyone else. Girls are much more comfortable admitting that they are not completely independent yet and they do need their friends."
It is this need to be seen to be tough and, above all, independent, not so much of each other, but of the school and the teachers, which undermines the boys' efforts.
Many of them know it. One boy in two agreed with the girls about showing off, and almost as many said they would like to work harder but were afraid of being laughed at. Perhaps most interesting was the high level of agreement between boys and girls that boys would do as well as girls if they tried as hard (girls 94 per cent, boys 90 per cent) and the almost equally high level of agreement that boys would do better if they "helped each other as much as girls do". But although boys knew peer group pressure was preventing them from doing their best, many felt powerless to resist because it is the peer group which establishes the masculine norm. Boys who are seen to co-operate with teachers are derided as "teacher's pets", which is by definition unmanly.
What these boys need is a change in their belief system so that the peer pressure that suppresses their chances is turned around and used to improve them. Exhortations from on high clearly have little effect; boys need to take control of the process of change themselves.
Using the survey resultsboys and girls to form separate discussion groups. The aim was to encourage the children to find solutions to the problems they had pin-pointed.
The most difficult task was getting them to focus on themselves. As we encouraged them to talk about how they could learn to take charge of their work, they would wriggle out from under the burden of their own responsibility - it was the teachers' fault, the girls' fault. Gradually some of the groups steered themselves towards collective solutions. A couple of boys (who had been extremely disruptive at times) saw that changing the anti-work culture lower down the school might be possible, by getting older boys to befriend younger ones and nipping bad attitudes in the bud.
In the end they agreed the key to improving performance lay in helping, rather than undermining, each other. As one of the groups put it: "Teachers and pupils should sign a contract and put it up in the room to remind themselves of their oath (also this oath can apply to some girls because a few of them are under-achieving as well). Also we can keep reminding ourselves of our aim and what will happen if we achieve it. We also need to think about other people, we need to be aware that when we get bored we don't destroy someone else's education. We promise to help ourselves and other people."
As these boys start their GCSE courses, it remains to be seen whether they have achieved a real shift in their collective idea of what it means to be male.
Angela Phillips is senior lecturer in journalism in the media and communications department at Goldsmiths College, London