Director M. Night Shyamalan describes the intriguing idea behind his new film Split, revealing how he utilized proven psychological studies about dissociative identity disorder and took them "one question further." After recalling his unique first conversation with star James McAvoy, he praises the "fearless" actor for his willingness to play so many different characters. Speaking of those many characters, Shyamalan puts the spotlight on the film's 10-year-old protagonist, Hedwig, and describes the challenge he and James faced in accurately portraying a child in a man's body.