Joseph Gordon-Levitt thinks he is "funnier" than the Marx Brothers.

The 30-year-old actor - who plays cancer patient Adam Lerner in new comedy '50/50' - explained while the movie deals with a difficult subject matter, it tells a "genuine, human story" rather than the slapstick style of the American family comedy act.

He said: "It's a different kind of comedy. It's not like the Marx Brothers: it's a story that comes from a genuine human story.

"It's not yuck-yuck jokes. It's funny because you feel for the characters. Plus, I'm funnier than all those mother- f*****s anyway."

While Joseph admits he was first shocked when he read the plot of the movie, when he realised screenwriter Will Reiser had based The Script on his own experiences of cancer, he appreciated it was "genuinely funny".

He added: "When I was first offered the part, my first instinct was, 'There's nothing funny about someone with cancer'. But Will found a lot that is funny.

"It's rare to find a story with character that feel like real human beings, and Will has written a comedy that shows that, even under the most horrible circumstances, funny things do happen. This felt real, and it was genuinely funny."