[quote=@canaryrose]
Can someone explain the appeal of joking about things that aren't jokes? Like joking about suicide, self-harm, autism, 9/11, ISIS... the list goes on and on.
[/quote]

As someone who jokes about like topics quite frequently, it's to take the edge off. When someone tries to make everyone sad by telling everyone about the most recent celebrity death, I think it's my duty to reverse this by lightening the mood. As with most things of this nature, you can't be indirect. You can't just say "hey, how about that football game?" You need to attack the offender's response directly by making light of something many consider tragic or scary. Insensitive? Maybe. But I consider myself one of the good guys.

[quote=@The Harbinger of Ferocity]
What is the appeal of people calling themselves, "insane", "random" or "evil"? 

[b]Attempted excuse for behavior[/b]?
[/quote]

I think that's the short version.

If you'd like it taken a step further, I've noticed that type of behavior is most prevalent at schools or other places with younger people. everyone forms a clique and uses it as an excuse to stay in their comfort zone or opt out of trying new things.

"I can't play sports, I'm a brainiac!"

"I can't play with dolls, I'm a jock!"

Though as we mature, we realize that it isn't as important to live out these "personas," and that we can be quite a few different people. When I'm working with customers, I'm friendly and courteous. When I'm around family, I'm goofy and silly. There's no reason for us to stick to some character archetype. different situations call for different behavior. But it is a learned trait that I feel most insane/random/evil people aren't aware of.