The only way I get a leading role in a studio picture is if Ryan Gosling can't play it, which is clearly the case with 'Selma.' If this was a non-colour-specific character, it wouldn't be me. It just wouldn't.

We start 'The Butler' in June and that's incredibly exciting for me because I get to work with the amazing Forest Whitaker again. It's a phenomenal script and a great, great role - I play his son. Oprah Winfrey is his wife and my mother. My character is a radical civil rights activist.

I have a bee in my bonnet as to how few black historical figures one sees on film; incredible stories, stories from which we are living the legacy and which just don't get made.

I just play intuitively and work the same way in the studio. I don't have any magical effects or anything that helps me to get my particular sound.

The only way we are going to get diversity is if the demographics of the decision-makers change... The odd-token bone thrown is not going to do it. Don't pat yourself on the back because you made that black drama; that's not diversity. It's got to be baked into the foundation of where the ideas flow from.

You can't afford for there to be gaps in your pool of knowledge when it comes to a character; otherwise, what ends up onscreen is generalized and unspecific.