Leonardo DiCaprio is very serious

Leonardo DiCaprio is “deadly serious” when he’s on a movie set.

The Titanic actor’s J Edgar costar Naomi Watts says that Leo is is very focused when he’s at work.

“Leo is very serious on set and works very, very hard,” says Naomi who plays the secretary to the late FBI Chief J Edgar Hoover in the biopic. “He’s got great charisma, he’s just wildly talented and he’s all about the work.”

DiCaprio recently admitted he never wanted to be an actor when he was growing up and his interest in environmental issues are all because he missed out on his true calling.

“Ever since I was very young I’ve been fascinated with nature and I actually wanted to be a marine biologist,” he said.

“That was a great passion of mine and why in the off season when I’m not making movies, I became more and more active as an environmentalist trying to be more vocal about issues I felt were important. I try to shed some light on some very topical issues right now.”