some people are bad

Why do some things that people do make us so angry/upset/agitated? I'm not talking about when someone shoots us with a gun -- I mean when they do something that doesn't really hurt us all that much but is still out of bounds (legally or socially), and ticks us off all out of proportion to how much it affects us.

Here is one answer:

PART 1:
I think at some core level we process things as Good and Bad. Or more accurately, Good For Me and Bad For Me. Things that feed/shelter/clothe us, taste good, feel good, make us secure, etc are Good. Things that threaten our safety or comfort or family/tribe or possessions are Bad.

To a lesser extent, we process people in the same way. Intellectually we recognize that people are complex, multi-faceted, etc, and that each person has a unique point of view, that life is complicated, etc. But life doesn't give us time to get to know and understand every person we come in contact with. Sometimes we feel called to make a quick judgement about people.

PART 2:
Our life and comfort depends on others. The kind of lifestyle we achieve through cooperation and specialization is utterly out of our reach if we're on our own. We need each other, and we need the societal and civil infrastructure to be in place and remain stable.

PART 3:
Tearing down is easy; building is hard. It takes continual effort by many people to fight the forces of entropy, ill will, and stupidity. Cars and houses and TVs and tractors and paintings and shoes and cans of soup and Hershey bars don't make themselves.

THE POINT:
To grossly simplify -- which we're good at -- we can categorize activities (or people) as falling into two categories: Either
1) building, making, preserving, healing or
2) breaking, hurting, destroying.
Category 1 people are those who love and help us, plus anyone who holds down a respectable job and contibutes to society -- especially nurses, teachers, counselors, builders, etc.
People who engage in non-helpful activities -- even if they're relatively mild -- are processed as Category 2 People. And category 2 is the one that includes rapists, murderers, arsonists, thieves, muggers, warlords, etc. We rightly fear and resent these people, because they threaten our well-being.

So when someone commits an act of pointless destruction, or messes with social stability or threatens the social order, we feel angry and upset because we process them as Category 2 people, and we ascribe to them all the evil that is represented in Category 2.

Activities that can put you in Category 2 can be as non-dramatic as:
- breaking a window
- stealing some small item
- tagging (that's graffiti for you old folks)
- driving erratically, flipping me off in traffic
- sabotaging the million-dollar-homepage
- darting out into traffic for fun

So anyway, I'm not sure if this makes any sense to anyone but me. But the non-pleonastic version is this: If you're not building/creating/helping, you must be a Destroyer, and such activities threaten me and make me feel angry.

Now you know.