In Sofia Coppola's The Bling Ring, Watson, 23, plays an L.A. teenager who becomes part of a criminal gang, and the actress says she has Kourtney, Kim, Khloe and a few other reality TV stars to thank for helping her perfect the role.
"I watched a lot of Keeping up with the Kardashians and The Hills, and I tried to understand the psychology of this kind of girl as much as possible," Watson told reporters at Cannes. "I didn't want her to be just a parody. The accent was hard as it was a particular kind of dialect. I also thought a lot about what her parents must have been like."
Though it's inspired by true events, Watson says the film's more than a crime movie.
"This really isn't a heist movie," said Watson. "It was how about these kids wanted to pretend for just two hours or so that they were actually Paris Hilton and living that life."
The film includes a cameo by Hilton, who was a victim of the actual crimes, and stars Leslie Mann as Watson's mother.