Why do people commit vandalism?

I’m not talking about political acts like throwing a brick through a bank window or tossing a corporate newsrag’s box off a bridge into a river; I’ve done those kinds of things myself, and I know well the causes of direct action, and I don’t regard it as vandalism in any case.

What I’m referring to here is senseless vandalism, like wrecking a public water fountain, or defacing a work of art. Why do people smear shit all over the stalls in public bathrooms? Why do they dump all the paper towels on the floor, or plug up the sinks with chewing gum?

Once, while I lived in a rooming house, I had spent weeks working on a paper model of a castle. If any of you have ever done a paper model, you know how delicate they are. Because you’re working with paper, you can’t even use large amounts of glue. I spent every night for weeks at the kitchen table with a magnifying glass, constructing tiny paper arbalests and catapults, putting down “grass” in the courtyard and oiling miniscule paper squares to construct translucent windows. When it was finally done, I left it on the table to dry.

The next morning I came down and found it missing. I searched everywhere and couldn’t find it. With a sinking heart I looked in the trash can and there it was, crumpled into a ball and tossed haphazardly in amongst the burnt popcorn and banana peels. I suspected who had done it (one of the other tenants) and confronted her on it when she came home. She freely admitted to doing it. At that point I was stunned by her nonchalance, so all I could do was ask her why. She seemed totally uninterested. She just shrugged her shoulders, said “I dunno” and walked away.

Why did she do it? What did she get from it? Why do people vandalize without seeming to profit from it in any way?