They swear, take drugs and claim to hate school and lessons. But they also hand in their homework on time, aim for A grades in all subjects and assume they will go on to university.
These two sides of the independent school girl may seem paradoxical, but teachers should not be concerned, says Pia Pichler, of Goldsmiths College in London.
Dr Pichler worked with Year 11 pupils in an independent girls' school in London. The pupils were given a tape recorder and asked to record several hours' conversation with friends. Her findings could help many teachers moving from the state to the independent sector.
The girls were often disparaging about schoolwork. One said: "Oh my God, I've got to write an English essay ... I've gotta sit down for an hour and wank on about some bollocky poem."
Similarly, they would talk about drugs, music and clubbing as a way of referencing their own "coolness".
One girl, Roberta, spoke at length about smoking cannabis with her older brother.
"I was going to school the next morning," she said. "We were all just ... sitting here ... just - I was so gone ... We are, like, drug addicts."
In state schools, teachers might fear that pupils with similarly negative attitudes to school could play truant, underachieve or drop out of education at the first opportunity.
By contrast, all the independent school girls were hoping to achieve A grades in their A-levels and planned to go to university.
Dr Pichler said: "Private-school teachers should be relaxed about the girls' anti-school stance. Teenagers negotiate their identities from moment to moment.
"They are expressing an anti-school stance to show that they're not complete swots, but at the same time struggling to do really well at school.
"It's about them trying to be ordinary adolescents in the very limited circumstances they have.
"They're trying to be cool."
In fact, many of the girls' attitudes and preferences reflected a desire not to be seen as stereotypically privileged pupils.
One girl, Nicky, attacked her classmates as: "Just so sheltered ... Me and Kim were the only people ... who weren't talking about going skiing at Val d'Isere."
Their crime, Nicky believes, is a lack of self-awareness.
Dr Pichler wrote: "Being 'posh' ... is not as much of an issue as lacking knowledge about one's own poshness."
So the girls strive to find a middle way. One girl speaks of the difference between two nightclubs, one populated by "all these Sharons and stuff" and the other filled with moneyed partygoers.
Independent school teachers should, therefore, avoid referring to their pupils' privilege.
"The worst thing you could accuse them of being is a stereotype," Dr Pichler said.
"The girls want to come across as 'real'. They do this by going to different clubs and smoking spliffs, but not by playing truant.
"Their rebellion is very, very mild."
- 'Talking Young Femininities and Gender and Spoken Interaction', edited by Pia Pichler and Eva Eppler, will be published by Palgrave Macmillan in 2008-09
PRIVATE GIRL TALK
Awareness of their own privilege
"I was sitting on my bed, like, a few weeks ago, and I just thought, 'Oh my God. I've gotta write an English essay.' And I thought, 'Hang on. All I've gotta do is sit down for an hour and wank on about some bollocky poem, yeah ... when other people have gotta, like, go down mines or whatever. How easy have I got it?'"
"On his last night here, it was me and him, and we had, we had, like, a couple of spliffs, yeah, and I was going to school the next morning, I remember, and, like, a few of his friends came round and we were all just - oh, it was ridiculous. We were all just sitting here and I was so gone, and everyone was just sitting there going, 'Oh my God.'"
"The Blue Moon, yeah, it's like a compromise because you've got, like, real people who, like, go to state school, or who, like, have jobs and stuff, and you've got, like, a few west Londoners, yeah. And it's just, like, a mixture of people, you know, and it's, like, just real people ... But then if you go somewhere like the Aquarium, you get all these Sharons and stuff, and they're just really embarrassing clubs."