Zhaozhou wrote:
Laughing is a way to ask for pity. You see someone is getting hurt and you laugh because you think "please, I don't want it happens to me".
I suspect in some cases, it's just a reaction to the stress of a situation. Someone laughing at an intensely tragic situation does not mean they find it humorous. There's a big difference between laughing hysterically during an emotionally intense situation and schadenfreude.
When I was almost 2, I had something fall on me. When my mom went to pick me up, there was a cut over my eye that was bleeding so badly that she thought I had actually lost my eye. I was rushed to the hospital, and every time my mom saw my face (the area around the eye had swollen pretty bad) she'd break out laughing.
Laughing during a tragedy is probably just part of an emotional overload. My mom wasn't entertained by other's misfortune and was no fan of slapstick (like Three Stooges type comedies, where the characters are constantly being subjected to insults and physical pain). I think it was a combination of horror, relief and delayed reaction that triggered the uncontrollable laughter.
Laughter is not always a great indicator of whether someone finds a situation hilarious or not. Laugh tracks are notorious for getting people to laugh at jokes that otherwise wouldn't get a dry chuckle. Most people don't find getting whacked in the humerus comedic, but there's a reason they call it the funny bone.