Once a character starts to laugh, all those around him start to laugh as well.

Truth In Television, but useful in fiction for getting a group some release from tension. Also, when a proud character is humiliated, this lets the crowd join together against him.

A character who does not join in is separate in some way -- this may be good, because the humor is unsuitable, or bad, because he's too proud to see the humor. It can result in an attempt to fake it.

Drives the Everybody Laughs Ending.

---

Examples

Anime and Manga

• In My Neighbor Totoro, once the father starts to laugh, the children are able to join in.

Film

• Mary Poppins: I love to laugh! Long and loud and clear! It's getting worse every year! The more I laugh, the more I'm filled with glee! The more the glee, the more I'm a merrier me!
• In Who Framed Roger Rabbit,
  • the weasels will set each other off. Since they are easily amused, it's less likely to spread beyond.
  • In the speakeasy, when the man saying he had seen a rabbit feigns that he has Harvey next to them, all the rest laugh together.

Live Action TV

• In MASH, when Blake talks of what kidders they are, Burns tries to join Hawkeye and Trapper John's laughter.

Web Comics

• In Sinfest, Squigley, on a trip, lands in Hell and makes a silly joke, and starts to laugh. The damned join in.

Video Games

• In Space Station Silicon Valley, hyenas use this as an attack.

Western Animation

• The Simpsons: Bart mentions that due to TV he has a very poor memory and can't remember even 8 seconds in the past. The rest of the family laugh at him. "No, really, I can't! It's a serious problem." They continue to laugh. After a moment he starts to laugh too; then while still laughing he anxiously asks "What are we all laughing about?"
  • In another episode Burn enjoys an Evil Laugh over his latest plan, and Homer (who the Evil Plan will directly affect) joins in the laughing. Then Burns stops but Homer keeps going for a while.
• In one episode of Futurama an Evil Laugh in a haunted house has this effect on Zoidberg.
  Voice: Bwhahahahahaha...
  Leela: What's that!?
  Zoidberg: I don't know, but it's contagious! Heh heh heh!

---