Jemma is a bright girl who took 13 GCSEs last summer. And how many did she pass at A to C? Three. "I didn't really go in much in Year 11," she explains. "I had my priorities wrong - my boyfriend." But Jemma's problems started long before that. She started bunking off in Year 10, but she had already fallen into behaviour and work habits that were bound to get in the way of her academic progress.
Like being very rude to teachers - especially women. "If they told us stuff, we wouldn't listen and we'd argue back," she says. "We'd make their life hell. And it worked. Some would swear back, cry, leave the room."
She says she was one of a group of about seven girls in the class in her west London comprehensive who hung out together and played up. And their attitude to work? "It was cooler not to."
"You'd make sure no one saw you working," she adds. "We sometimes used to go in very early and do it quickly, before school."
Jemma is typical of a growing number of teenage girls in school, according not just to anecdotes from teachers but to a new, government-funded study that turns conventional wisdom on its head.
Sensible and hard-working to a fault has been the view of girls as they have streaked ahead - in Sats, GCSEs and A-levels. And those under-achieving boys? Well, they're lads, aren't they? Think it's not cool to work. Now, however, evidence from teachers and pupils at six comprehensives in the north of England has found that more and more girls are starting to behave like "laddish" boys.
The "ladette" behaviour which was first identified in the 1990s - loud, assertive, binge-drinking - has filtered down to schools.
Catherine Tate's (left) portrayal of the "Am I bovvered" teacher's nightmare is typical of the kind of girl who has potential but is in school on sufferance.
Young teenage girls have become much more assertive and confrontational in school. And, to an extent unsuspected by their teachers and surprising to the researchers, many now have the laddish attitude that it's uncool to work. The study, led by Carolyn Jackson at Lancaster University, found 13 to 14-year-old girls just as reluctant as boys to look like hard-working "geeks".
In fact, the proportion of girls and boys who admitted to hiding work and effort was about the same: 37 per cent and 36 per cent respectively.
As they desperately try to balance academic demands and popularity, more and more girls are either neglecting to work or revise properly, so they can blame lack of effort if they fail, or pretending not to work (but actually catching up in private) so they stay popular.
Why does this matter? On average, girls are still doing much better than boys, aren't they? And surely a more assertive, devil-may-care attitude might be better for girls than the excessive conscientiousness that can make them ill?
Dr Jackson stresses that there is a positive side to girls' growing assertiveness and self-confidence. But she cautions against over-generalising about the two sexes.
"Not all girls are getting good exam results and not all boys are 'failing'," she says. "The picture is far more complex. There is evidence that laddish attitudes and behaviour can impede the progress of some pupils in school.
"My research suggests that it's wrong to regard this as 'just a boy thing'.
So if we're worried about boys' under-achievement, we should be worried about girls too."
In her recent book based on the research, Lads and Ladettes in School, (Oxford University Press, 2006) she also points out that a laddish insouciance about academic work is likely to be far more harmful to some pupils than others.
There is the unfair advantage enjoyed by the tall and good-looking - and, in the case of boys, the athletically gifted. These, she writes, "earn points on the 'cool ladder' that can be used to offset points lost for undertaking school work".
Above all, there is class. Middle-class pupils, she says, with lots of space and computers for homework and internet chat - and the money for designer clothes - are far more likely than poor pupils to be able to balance social and academic demands.
Dr Jackson found laddish attitudes to work equally strong in single sex and mixed, high- and low-achieving schools and among pupils from middle-class and poor backgrounds. Yet her findings are greeted with surprise in some quarters.
Girls still seem to be working their socks off in some areas, judging by the reaction of several nonplussed heads approached by The TES - although they conceded that the (small) number of really challenging girls was on the rise.
But perhaps part of the reason for that was that the heads in question were male. Intriguingly, not only did teachers in the Lancaster study generally underestimate teenage girls' disengagement from work but male teachers were particularly blind to it.
At one school, a male teacher suggested that there was no issue with ladettes in school, while one of his female peers talked about them at length.
"Girls don't act up quite so much with male teachers," a female teacher who works with difficult pupils in the Home Counties told The TES. "And men don't pick up so much on the subtleties."
From her description, "subtleties" is hardly the word for it. "I've been shocked by girls in the past few years," she says.
"They're much more confrontational and aggressive. Girls used to be more passive than boys - now, you wouldn't really notice the difference. The submissive side's gone.
"At one time, if the head heard loud voices in the corridor, it was likely to be boys. Now, it's just as likely to be girls. The biggest shock is the swearing and casualness of their language."
She works with low achievers, the vulnerable and disaffected who certainly think it's uncool to work.
"It's not that they're not bright," she stresses, "but they're not willing to apply themselves because of their fear of failure. It's easier to drop out and just give up."
Teachers in the schools in Dr Jackson's study also expressed dismay at the growing "in-your-face" attitude of girls, which they clearly found difficult to manage.
"I'm very much in favour of women being assertive," said one, "but I don't like the element of arrogance that goes with it. You've got to draw that line. Sometimes they are bordering on rude."
But Dr Jackson identified an element of double standards. A number of the teachers suggested that laddish girls were more difficult to deal with than laddish boys, or said that laddish boys were more charming and less vicious than their female counterparts.
They were also more concerned about the way laddish girls behaved out of school, especially with the excessive drinking, sexual promiscuity and fighting.
The girls identified as ladettes did little in their interviews to allay such fears. Almost all said drinking and talking about sex was important to make them look "good" among their peers but Dr Jackson could not establish the true extent of such behaviour.
So why are more girls turning to laddish behaviour and attitudes and what, if anything, can be done about it?
Dr Jackson suggests that, as with boys, much laddish behaviour is a defence mechanism against fear of academic failure - and that the current stress on high stakes testing is making it worse.
"Laddish ways of behaving can protect individuals from the damaging implications of academic failure (that is, that they are 'stupid') by blaming other factors (for example, that they did not do any work)," she writes.
Laddish ways of behaving can also make academic success appear effortless.
The beginnings of a solution, Dr Jackson suggests, might lie in a move away from a competitive, performance-based approach in the classroom and to-wards a more co-operative approach to learning, with pupils working together towards common goals.
Then, she says, pupils might feel able to undertake challenges without the risk of being labelled stupid." She would also like to see more effort to tackle the notion that effortless achievement is an ideal.
And Jemma? She's on the right track now. A student at Richmond upon Thames College, she is aiming for the "highest marks I can get" in her GCSE English resit and is taking a BTec in drama. "I've matured now," she says.
"I'm doing it for myself."
And she no longer cares about being cool
TOO COOL FOR SCHOOL
The research into 'laddish' attitudes and patterns of behaviour among 13 and 14-year-old boys and girls was funded by the Economic and Social Research Council and carried out by Dr Carolyn Jackson of Lancaster University. Six comprehensive secondary schools in the north of England were involved: four co-educational, one girls' and one boys', covering a mixed social and ethnic intake and a range of achievement. About 1,000 pupils completed questionnaires and 150 pupils and 30 teachers were interviewed at length in the academic year 2003-04.
A book based on the research - Lads and Ladettes in School, by Carolyn Jackson - was published by the Open University Press in October.