The Split star Stephen Mangan on his past life studying law – and why he's much better suited to being an actor

You play Hannah’s husband Nathan. How is their relationship?

Our marriage gets put through the wringer. It’s gone a bit stale, work has taken over family life and everything’s so busy, but like a lot of marriages we’ve taken it for granted. Abi Morgan’s script allows very little black and white – you could argue almost anyone’s corner on this show. Hopefully you’ll want to slap each character at various points, and give each of us a hug as well.

Does it cause you to re-examine your own relationship?

You start to think, what if my wife [actor Louise Delamere] or I put a bomb under our marriage? How would we cope? We’ve got three kids and the thought of it not working out is horrifying. Having said that, the truer dramas are, the more uncomfortable they should make you feel. If you watch a show about someone whose dragon is dying, it’s very easy to distance yourself from what they’re going through, but when you’re watching professionals with families, trying to cope with busy work and family lives… It can be very close to home. We want to cause people emotional pain!

Was being a law graduate useful for your role in The Split?

The only thing I can remember about law is how to spell it. It feels like another life.

Would you have made a good lawyer?

No, no. Law takes the mess of human life, tries to codify it and makes it very dry. I remember all these criminal law cases about what constitutes burglary. It’s much more interesting to think, what does it feel like to be the person lying in bed while someone’s climbing in through your window with a knife? I made the right decision. The legal world hasn’t lost anything!