There are lots of different kinds of laughter. That is to say, the activity may be similar across different occasions, but what it means is very different. Think about the number of different verbs we have in English for different forms of laughing: guffaw, titter, snicker, giggle, chuckle, just to name a few.
One of the things I notice about laughter is that there are appropriate and inappropriate times for it.
When someone else tells a joke, that's an appropriate time, usually. But it will depend on the perceived appropriateness of the joke to the social situation, and also on the rank of the joke-teller and the listeners.
When your father tells you he's angry with you, that's not an appropriate time. I have seen this in my household (and experienced it myself, so you can substitute "mother" for "father" too), and believe me, when you're mad and someone laughs, it makes you even madder.
When you're playing a game or otherwise sharing social experience, and experiencing delight, this is an appropriate time.
When someone tells you something you've never heard before, and you think it's interesting, this is not an appropriate time.
But there's a lot of gray area. In particular, laughter is often a response to nervous discomfort. Humor often takes advantage of precisely this in order to get people laughing about taboo topics, or about other areas that make people feel on edge.
And when you think about it, isn't that most likely the response you're getting from a child when you say you're angry? What sounds like insolence may be nervousness (and yes, a degree of recklessness).
And when someone tells you something you've never heard before, and you're delighted, what do you do?
Well, I often run into situations where people will say things to me that I find so charming, so delightful, or simply so perfectly true and illuminating that I will laugh. And then people say to me, "I'm not kidding." Lucky for me, I'm not doing this in a work situation where I might be penalized for my behavior. Still, I'm stuck saying, "Well, I know you're not kidding - I was laughing because what you said was just so perfect/great/etc."
When you think about it, this is a great element to play with in your worldbuilding. What kind of alternate attitudes about laughter might there be? What would be an appropriate time to laugh that humans didn't recognize but someone else might? What would constitute humor in another culture very different from our own?
It's something to think about.