Joaquin Phoenix’s Joker Laugh Was Medically Inspired

There is no trait that’s more important to The Joker than his laugh. Since his earliest on-screen portrayals, all the way through to today, every actor that’s portrayed the Clown Prince of Crime has had their own distinct spin on it.

Joaquin Phoenix, who’ll play the character in Todd Phillips’ upcoming Joker, is no exception, and in an interview with Il Verdini (h/t CBR), the actor revealed how his cackling came to be.

“I started [with the laugh],” Phoenix said. “I watched videos of people suffering from pathological laughter, a neurological disorder that makes individuals laugh uncontrollably.”

This inevitably reveals a bit about Arthur Fleck, which is the character’s name before he becomes all-consumed with his clown-paint persona. By making it a pathological disorder, it potentially taps into some deep-seated psychosis in his character, turning him from a work-a-day street clown into the scourge of Gotham City.

RELATED: Todd Phillps Says Joker Movie Won’t Follow Anything From The Comics

Director Todd Phillips’ original, standalone origin story Joker explores the world of—and according to—Arthur Fleck. Indelibly portrayed by Joaquin Phoenix, Arthur is a man facing the cruelty and outright scorn of society, along with the indifference of a system that allows him to spiral from vulnerability into depravity. A clown-for-hire by day, he strives to be a stand-up comic at night…but finds that the joke always seems to be on him. He’s out of tune with everyone around him, as evidenced by his uncontrollable, inappropriate laughter, which gains momentum as he attempts to contain it, exposing him to further ridicule—and even violence.

Arthur, who devotes himself to caring for his fragile mother, seeks out every father figure he’s never had, from wealthy businessman Thomas Wayne to TV host Murray Franklin. Caught in a cyclical existence teetering on the precipice of reality and madness, one bad decision brings about a chain reaction of escalating, ultimately deadly, events.

Phillips (The Hangover trilogy) directs from a screenplay he co-wrote with writer Scott Silver (The Fighter), based on characters from DC. The film is being produced by Phillips and MCU mainstay Bradley Cooper under their Joint Effort banner, and Emma Tillinger Koskoff. It is executive produced by Richard Baratta, Joseph Garner, and Bruce Berman.

Joker opens in theaters everywhere on October 4.