"I live on an estate," 17-year-old Gianinna Aguilar says. "And people smoke on the stairs. They smoke weed on the stairs, and I see them every day. But I'm not going to do that. I don't want to be like that. It depends on your background."
There are nods of agreement around the table. "Background, background," murmurs McLloyd Vuong. "I have a friend who's quite posh. I've noticed that every time I go to his house, his parents will have conversations - more adult conversations. Harry's parents talk to him about politics, the stock market. My parents... that doesn't go on."
McLloyd and Gianinna are participants in a one-off focus group session at the central London offices of the RSA, a hybrid of think-tank and campaigning charity. It is developing plans to tackle disadvantage and class prejudice in schools, using intervention and mentoring programmes.
The aim of today's session is to find out what the potential recipients of programmes of this type believe are the biggest challenges facing them. In an imposingly high-ceilinged Georgian boardroom, seven pupils from the Lambeth Academy gather around a table.
"They're living proof that social mobility is a very serious issue," says Ricardo Pavez, Lambeth assistant principal. "They're very driven, ambitious young people. But they live on estates, so along the way they have to work doubly hard."
The pupils begin by discussing their own south London background and concomitant limitations. Some have to care for younger siblings; others combine schoolwork with part-time jobs.
Gianinna neatly summarises the situation with a pithy one-liner: "People who don't have money, they don't achieve.
"You get these parents who" - she lowers her voice - "don't give a crap. People aren't encouraged to do their homework enough."
There is a chorus of agreement. The problem, they say, is not lack of parental interest: it is lack of parental experience. "My parents are really insisting on my going to university," says 17-year-old Hennah Sacoor. "But they don't know which university is good. They know that Oxford and Cambridge are good, and that's it."
Becky Francis, RSA director of education, is taking notes. Academic research, she says, has shown that there is often a huge gulf between the values that working-class children grow up with and those they encounter at school. Middle-class children, by contrast, face far less dissonance.
"Already, working-class kids feel like fish out of water," she says. "Those differences come into play even at a very young age. If you're told you're a failure, why would you bother trying?"
The RSA has a network of 27,000 fellows, including actress Dame Judi Dench, fashion designer Dame Vivienne Westwood and Sir Tim Berners-Lee, inventor of the World Wide Web.
Professor Francis hopes the fellows will provide advice and support for disadvantaged pupils. But, she tells her focus group, the aim is to provide the assistance that they actually need, rather than the assistance others think they need: "If you think our ideas are rubbish, it's really important that you say so."
And so the teenagers offer their views on school-based social divides. "There's a gap between the houses and the estates," says McLloyd. "They're not mixing."
Across the table, Daniel Dennis, 17, elaborates. "No offence," he says. "But when people first come into secondary school, they go into their separate groups. Phoebe, Freddie, whatever - the upper-class people - go into one group, the middle-class people go into their group, and the working-class people go into their group."
The best possible intervention programme, the teenagers believe, would prevent such schisms from arising. "Socialising, mixing," McLloyd volunteers. "Community events can get rid of differences." Primary school plays or fetes, they suggest, can highlight similarities and minimise differences. "I think schools should look at the background of each student, and mix them up, mix classes," McLloyd adds.
This would be the ideal. But the pupils are old enough to realise that reality is rarely ideal. And if class difference cannot be annihilated at primary school, it must be mitigated at secondary. The key, they all say, is to show pupils why education is important.
"From the first day of secondary, there should be someone who explains why it's good to be there through the whole of education," Daniel says. "They can explain the advantages of paying attention."
Because pupils of this type would be relatively young, teachers could even make the session fun for them: imagine how many Playstations you could buy with the increased earning potential that good qualifications afford. "It's true," Daniel says. "If you work hard and go through university and get a better salary, you can get more things.
"Know what you're aiming for. If you don't know what you're aiming for, then you're lost. When you're younger, you believe everything. Make them believe that they can get somewhere."
But merely convincing pupils that they need to learn is not enough.
"You need to educate parents about the importance of education," says 17-year-old Pranay Singh. "Talk to them about how to encourage your children, how to help your children."
Parents could also be encouraged to provide realistic support and guidance for their children. Gianinna's parents, for example, repeatedly upbraid her for achieving Cs, rather than As. "They don't understand how hard it is because they haven't been through it themselves," she says. "They just want me to do really well, and you can't blame them for that."
But, the teenagers unanimously agree, it is vital that whoever runs these sessions is someone to whom they and their parents can all relate. "If you put someone from a posh background with someone whose mother has a drink problem, it wouldn't work," says Gianinna. "They wouldn't appreciate where each other was coming from. You'd just feel patronised."
Professor Francis turns another page in her notebook: all this will be reported back to the RSA fellows. And, sitting opposite her, Mr Pavez nods, and takes down notes of his own.
"We discuss these issues repeatedly," he says. "But no one ever asks the young people what they think. They just want access to opportunities. They really have to strive. It's for every teacher to remember that, and open doors for these young people."