"The bedroom of my childhood memories is a small room with sloping eaves in the attic of the family home, a tall semi-detached house in Oxford," writes James Mollison in the introduction to his new book.

"It's where I slept between the ages of five and 19. First decorated with wooden animals from Kenya (where I was born) and a teddy bear made by Mum, I progressively made the room my own, its changing contents reflecting my identity, interests and aspirations as they evolved through childhood... My bedroom was my personal kingdom."

Titled Where Children Sleep, the book was produced with the support of Save the Children and Fabrica, the Benetton-funded creative foundation he spent a formative year with in his early twenties, and who gave him a commission to come up with an idea for engaging with children's rights. Mollison immediately thought of this bedroom and how important it had been to him, and decided to shoot other children's rooms, along with portraits of the children who slept in them, shot against plain backgrounds.

"My thinking was that the bedroom pictures would be inscribed with the children's material and cultural circumstances - the details that inevitably mark people apart from each other - while the children themselves would appear in the set of portraits as individuals, as equals... just as children," he writes. In the event he soon realised how lucky he'd been to have his own room, in a journey that took him from 14-year-old Prena's cell-like sleeping quarters in Nepal [below left], to the dormitory that Lay Lay, a Thai four-year old, shares with 21 other orphans.

The text that accompanies the images, outlining the children's circumstances and aspirations, only makes it all the more poignant. Prena works from 5am to 6pm for the equivalent of $6.50 a month, which she sends back to her parents. Other images show children who are materially much better off, but perhaps not in the ideal place psychologically. Jasmine is four, lives in Kentucky, and sleeps in a room full of sashes and trophies from child beauty pageants. She's dressed in a neat black-and-yellow outfit and wearing make-up, posing with a fixed but dimply, wide smile.

"Her spare time is completely taken up with preparation and rehearsal," writes Mollison. "She practices her stage routines every day with a trainer who teaches her new steps. Each weekend, she participates in a different pageant, arriving on Friday afternoon, performing on Saturday, and attending the crowning ceremony on Sunday. By the end of the show, she is quite exhausted."

Mollison claims he doesn't have an agenda and isn't qualified to lecture anyone on the state of childhood today, but at times can't quite resist slipping into slightly didactic terms, as the quote above shows. Perhaps that's down to the audience the book is intended for – young children (it comes with a glow-in-the-dark front cover), inevitably from more privileged countries. "I hope this book will help children think about inequality within and between societies around the world," he says, "and perhaps start to figure out how, in their own lives, they may respond."

Where Children Sleep is published by Chris Boot (ISBN: 978-1-905712-16-8), priced £20. www.chrisboot.com.