system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why were laugh tracks so widely used on sitcoms in the past? Did people not know when they were supposed to laugh?

I’m rewatching some older sitcoms and the laugh track is so odd to me.  I remember thinking nothing of it growing up, but now that I’ve been watching sitcoms without it, it feels completely pointless.  Who thought it was a good idea and why?
gpt
Originally sitcoms were filmed with an audience, and you would hear their reactions. In the 60s, TV networks tried inserting laughter into sitcoms, and discovered that focus group audiences found the shows much funnier than with only "natural" laughter. So yeah, it does work. Laughter is contagious. Humans are weird.