Cillian Murphy thinks his low-key approach to life makes it easier to appear convincing on screen.

The 38-year-old is notoriously camera shy - preferring to live a quiet life with his wife Yvonne McGuinness and their two sons, Malachy and Aran Murphy, in north London - and he says being so reserved about his life away from the silver screen is beneficial for his career.

'The Dark Knight Rises' star explained to the Guardian newspaper: ''Logically, the less people know about you, the more convincing you are playing someone else. It's glaringly obvious to me.

''I get the bus, I get the tube, I go to the shop and get the milk and do normal things. I would hate it if that became impossible.

''As an actor, you're supposed to be playing real people so it seems essential to live like a normal person.''

Cillian attributed his career success to good script writing, saying: ''The only thing I've tried to stick to, and I've repeated it ad nauseum, is to follow the good writing.

''I don't want to go to America and up sticks to wherever a shoot may be for 12 months. I've got young kids, you don't really want to uproot the family for a year.''