The `Gnomeo and Juliet` actor admits he finds it easy to stand out in a crowd thanks to his smooth-talking ways, which he believes have boosted his chances at doing well in auditions.
He explained: "I`ve played roles where my character has to be quite charming and I`ve found it quite easy to do. I think some of it is in my bones but some of it is more deliberate. I remember that it was never that difficult for me to get a director to look up and pay attention to me. Mind you, I don`t know if that`s necessarily charm.
"Even now when I`m auditioning, I`ll often stick in a wee thing or an extra line that I know will be disarming for the lady I`m acting with... Well, not necessarily disarming. Hopefully non-repellent."
The 31-year-old Scottish star - who has a seven-month-old son, Andrew, with wife Anne-Marie Duff - thinks his likeability is a "bit weird", particularly as he isn`t always a gentleman.
He added to Seven magazine: "I can assure you there are lots of occasions when I am not charming at all."