The rooms are filled with objects and mementos from everyday activities, a sort of 3D scrapbook. Amber, 14, has a swing that broke under her in the park and a sofa she found abandoned on the side of the street. "Her mum wasn't very pleased about it and kept offering to take it to the dump," Newson says. "But teenagers want to bring a bit of the outside world in. It's about showing off your expanding cultural life, letting people know that you're broadening your horizons outside the home."
At one end of 17-year-old Emily's room, a strip of black-painted wall has been scrawled over in coloured chalks. She had planned to draw on this wall herself, but her friends covered it in personal messages during a party.
"Your world is still quite local at that age, and your friends are very important," says Kyna Gourley, who took the photographs for the project. "There's something fascinating about the time between adolescence and adulthood. It's such an interesting life stage, when people are on the cusp of finding out who they are."
This blurred line between child and adult, between home comfort and independent rebel, is one of the most prominent themes of the display. In one room, a soft toy of Pilchard, Bob the Builder's cat, pokes its head out of a blue set of shelves stacked haphazardly with books, on top of which perches a red Accident & Emergency sign presumably stolen from a hospital. A half-deflated birthday balloon hovers nearby. "As soon as I walk in there it's like a sigh of relief," says Pearl, its 17-year-old occupant. "It's so tuned to me... I just feel it's like a house inside a house."
Freya, 15, has swaddled her room in a warm, red glow, where stuffed toys of Maisy the mouse and Babar the Elephant mingle among more elegant cushions on the bed. Large flowers have been hand-painted on the walls and a Monet print of a bridge over water lilies is framed with twinkling fairy lights. "It's, like, my space and I put things up that I like, that are special to no one else," Freya says. "It's just the one place that is very me."
To be sure, from JD Salinger to Kurt Cobain and many more besides, the teenage experience has been well documented. But Newson wanted to capture not just the soul-searching nature of these few years in a person's life but the way that has changed over the generations.
One of the most notable differences between the life of teenagers today and that of their parents' youth is the advent of social media. Whereas teenagers in the Sixties and Seventies would have relied on the family telephone in the hall - a much more exposed place to conduct their personal life - their children manage their social affairs from the safety of their own rooms.
This makes the bedroom a more personal, private space, where a young person can speak on the phone without an adult presence, but also a more public space, where a teenager might be having five conversations at once - including visual ones that allow the other person to see the room, such as FaceTime or Snapchat.
"It's not unusual for parents to decide that one of the teenagers should have the largest room in the house," Newson says. "And there are a lot more double beds in their bedrooms now." This is also related to the internet - a function of our increased ability to work and socialise from our own rooms - but also, perhaps, of a more liberal attitude towards parenting.
Although the exhibition focuses on teenagers' propensity to collect and savour mementos of their life experiences, it will appeal to a wider audience - because, of course, this habit isn't limited to the under-20s. One of the parents from the study had kept a lot of these personal items, Newson recalls, and then lost them in a fire. "They're only bits and pieces - scraps, really - but you don't realise how important these things are until they're gone."
