Volatile British actor Christian Bale modeled his sociopathic central character in the big screen thriller American Psycho after couch jumper Tom Cruise.

According to Mary Harron, who directed the 2000 film, Chrisitan came up with the idea of using Tom as inspiration for playing serial killer Patrick Bateman after seeing him appear on the Late Show with David Letterman.

“We talked about how Martian-like Patrick Bateman was, how he was looking at the world like somebody from another planet, watching what people did and trying to work out the right way to behave,” Harron told The Courier Mail this week.

“And then one day he called me and he had been watching Tom Cruise on David Letterman, and he just had this very intense friendliness with nothing behind the eyes, and he was really taken with this energy,” she said.