Loosely inspired by the real-life home shopping entrepreneur and inventor Joy Mangano, the film features Lawrence co-starring alongside Cooper for the first time since 2013's "American Hustle."
"I feel very safe [with Lawrence]," Cooper, 40, said. "I can turn my brain off as an actor. I think, having to learn that dance routine [in 2012’s ‘Silver Linings Playbook’], we really didn't know each other at all. Talk about being vulnerable with somebody."
Lawrence, who snagged a Golden Globe nomination for her role in "Joy," agreed that her on-screen chemistry with Cooper comes naturally.
"David made us a bizarre kind of form of siblings, in a way," Lawrence, 25, said.
"Joy" will be released in theaters Christmas day.