Actually, I find that I am less likely to laugh out loud while watching TV with company unless all of the below conditions are met:

1. There are a large group of us
2. It's really late
3. We are all good friends
4. We've eaten too much just recently

And pretty often even then I will laugh at the bits no-one else considers especially funny. I have particular difficulty when people tell me jokes, because I usually want to indicate that I'm amused by the joke (when it's even slightly amusing), but I rarely laugh out loud in front of other people.

But I think the phenomenon you are referring to in the OP is exactly the reason they invented canned laughter, which I abhor.