You're the only member of the cast who wasn't raised in India. What did you do to fit in?
When I got there, I was the same skin color as everyone else, so I decided to take off the Nike T-shirt and walk down the street. But I still kept on getting stares and I didn't know why. I just walked different and acted different. So whenever I had free time, I'd just go out and walk and learn how to relax and put my hand on my hip. There is a difference to it there. It's really intimate, especially in the slums. Everyone knows everybody. It's such a feeling of community, which you don't really get in London.
Anil Kapoor, who plays the host of the Indian version of "Who Wants to Be a Millionaire," is a star in India. Were you nervous working with him?
Whenever I used to go to my grandma's house, he was the guy I would watch. He was the Bollywood superstar. To be working with him was just something else. Out there, he's looked up to like a god. When we were doing the "Who Wants to Be a Millionaire" scenes, we had a live audience, and they were bewildered when he walked in the room. The A.D.s couldn't get them to be quiet, so Anil ended up directing them, and they were listening to him like a teacher. Like a guru.
What about Irfan Khan, who's better known to Western audiences from movies like "The Namesake"?
I'm his biggest fan after this film. The way he uses his eyes is tremendous. The subtlety with which he acts, sometimes you don't even think he's doing it. So I took that on board. I was like, "If I'm going to play this guy good, I've got to home in on the eyes," and it really worked. I'd never played something subtle before. In "Skins," my character was a total goofball. This was a massive learning curve for me and a master class from great actors.
The movie spans the emergence of India as a global economic power. There's a scene where Jamal and his brother look out at a sea of skyscrapers where their slum used to be.
That scene was really hard for me. I had to detach myself from who I am. I was playing it upset and mortified but if you really got into the mind of that character, you can imagine if someone built a massive tower block over your slum, which you'd left ages ago, you'd be like, 'Wow. That's amazing.' I really had to get out of that Western frame of mind and stop feeling sorry for myself. These kids don't. It's survival of the fittest and if you feel sorry for yourself, you're not going to get anywhere. Pull yourself up and get on with it.
What was it like filming the big Bollywood-style dance number?
When I first read the script, I thought it was a metaphor for their happiness: "The whole station breaks out in a dance of happiness." Then one day, Danny came to me and said, "I've got a choreographer for you and you're learning a dance tomorrow." I never knew I could move my hips that way. I'm one of those guys, if you go to a party, I'm at the back having a drink. And I was out in the middle of India's busiest train station, dancing along with all these professionals. I really got into it by the end.
Adams is a freelance writer.