I do not laugh when feeling anything besides amused, to the best of my memory (which granted isn’t very good these days). Typically when I laugh “inappropriately,” it’s because something I find amusing randomly popped into my head and has nothing whatsoever to do with anything else. So I do sometimes laugh “inappropriately,” just not in reaction to any sensation or emotion that most people don’t associate with laughter.
Now, crying, on the other hand... pretty much any strong emotion makes me cry. And even sometimes very insignificant things make me cry - it could be something as simple as a dead leaf on a plant. And then sometimes it pretty much requires a strong emotion of some kind. It’s really obnoxious when I’m crying because I’m angry or frustrated, or want everyone to just leave me alone but can’t hide the fact that I’m crying, which draws unwanted attention to me, or something really didn’t upset me that much but I’m crying over it anyway.
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Yet in my new wildness and freedom I almost welcome the bitterness of alienage. For although nepenthe has calmed me, I know always that I am an outsider; a stranger in this century and among those who are still men.
-H. P. Lovecraft, "The Outsider"