The Oscar-nominated director cast the Scottish star in his latest cinematic masterpiece, Split - a thriller about three girls who are kidnapped by a man with 23 different, diagnosed personalities. Although Shyamalan hadn’t met MCAvoy before choosing him to play the terrifying Kevin, he quickly realised the actor was the perfect candidate as he was already a “huge admirer of his elegance”.

“I feel he’s the most courageous actor,” the filmmaker told Empire Online of MCAvoy. “When you get to that skill level of acting, I understand actors’ tack towards biopics. They want to go for it, they want to be dangerous but they want the patina of protection which is, ‘I was acting crazy because he was’. It takes a very different courage to really go for it in an original movie. Especially late in a career.

“I’m not sure his peers that are at his level of acting would have been as courageous. He almost doesn’t have a fear button.”

MCAvoy wasn’t initially intended for the film as Joaquin Phoenix was originally rumoured to play the lead, but Shyamalan felt confident the Atonement star had the ability to pull off multiple personas, from a child to an old woman.

Asked if he expects any controversy to come from his representation of dissociative identity disorder (DID) in Split, Shyamalan - who also wrote the screenplay for the feature - insists there’s been no negative feedback so far.

“For the people who’ve seen it, it lands. People who come to see my movies, you’re coming to see a drama masquerading as a genre piece. People have hopefully figured that out by now. I make dramas, guys,” he explained. “Clearly it goes to fantasy at the end... everybody wants controversy but surprisingly there’s been very little. People have been enjoying it in the way it was intended, which I’m very happy about.”