We know that Leonardo DiCaprio is an electrifying actor, an ardent environmentalist and a supermodel magnet.

What hardly anyone outside his inner circle knows is perhaps the most surprising thing about him. His idea of fun is to sit around with his buddies and make up ridiculous characters and then try to do their voices. “I’m actually an incredible goofball,” says DiCaprio, whose new film, Shutter Island, opens in two weeks. “I do imitations and joke around all day. I keep things light in my life.”

DiCaprio tilts his head, lifts his eyebrows and puts on a small, “I know it’s hard to believe” type of smile that is supposed to convince me. It’s a Sunday afternoon in London, and he is stretched out in a plush hotel suite. 

At 35, DiCaprio is one of the most acclaimed actors of his generation, a three-time Oscar nominee who has blockbuster hits and a heavyweight collaborator in director Martin Scorsese.

If he does, as he says, keep things light, he has yet to show us that side of himself onscreen. Even in Catch Me If You Can DiCaprio found a way to add some anguish to his quick-witted con man.

“It’s never a conscious thing,” he says. “I just try to be a part of films that move people. A lot of times, those are the darker side of humanity, I suppose.”

Shutter Island could be his darkest to date. DiCaprio plays a U.S. marshal investigating a mysterious disappearance at an eerie institution for the criminally insane. Digging for clues, he and his partner (Mark Ruffalo) uncover a disturbing secret just as a hurricane hits, trapping them on the remote island. “People should watch this movie two times,” DiCaprio suggests. “It’s going to seem like one thing on the first go-round and something entirely different on the second.”

DiCaprio says he wasn’t fully prepared for the depths his character, who suffers from post-traumatic stress disorder, had to go to. “There are sequences toward the end, some of the more hard-core weeks of filming I’ve ever had, where we kept pushing this character to places that are almost uncomfortable to witness.”

The word “emotion” comes up often when DiCaprio talks about his work. He sometimes says things like “the gravity of the character,” or “until you’ve lived a portion of this person’s life on set, moments in scripts can be passed by with a flick of the page.”

But he’s not always Mr. Dramatic. He’s also a reality TV junkie. “I find it the funniest and most entertaining stuff on TV,” he says, cracking up. “We’re so hilarious, when we don’t even try to be.”

Following his breakthrough role in 1993’s This Boy’s Life, DiCaprio had a choice: collect big money for a Disney movie about witches or pursue this other role he might not even get, as a mentally disabled teen in What’s Eating Gilbert Grape. He chose the latter, a decision that paid off, with interest, when DiCaprio scored his first Oscar nomination. “There were a lot of people urging me to go in the other direction,” he says.

Shutter Island co-star Ben Kingsley says DiCaprio’s performance in 1996’s Romeo & Juliet “was the best Romeo I’ve ever seen,” which is saying something. Kingsley has been a member of the prestigious Royal Shakespeare Company since 1967.

Scorsese (who directed The King of Comedy) says: “The thing is, you have to have a really strong sense of humor in order to do these dark roles. On Shutter Island, too, as tough as it was to make, there were very funny moments between Leo, Mark and myself. Ask him about the rain.”

When I do, DiCaprio chuckles. “It was insanity,” he says. “At one point, I think I was singing Bob Dylan tunes. We had these giant rain machines going during one scene, and Mark and I couldn’t hear a word we were saying. Not only that, we couldn’t see because they had giant fans blowing stuff and trees falling on either side of us. It became almost like a slapstick routine.”

Which makes you wonder, what kind of comedy would DiCaprio go for? When asked about it point-blank, he’s stumped: “Peter Sellers had some great comedic roles. Those would’ve been amazing to try.” And then it hits him. “Yeah, that’s it: Dr. Strange love,” DiCaprio says. “Dark!”

What makes Leo laugh

TV:
DiCaprio loves reality TV shows. “I don’t know why TV didn’t have [them] before, because you can’t replicate real-life drama or the idiocy of the human race.”

YouTube:
“I have a bunch of videos I watch. ‘Good Day Mr. Kubrick’ is this guy Brian Atene’s audition tape for Full Metal Jacket. It’s phenomenal.” Other favorites include the “Kung Fu Auditions” series and “Jumping Lizard.”