Cars make people lose 20 IQ points the minute they step inside.

My theory is that cars, being uniquely private spaces moving on public roads, become bubbles of highly territorial spaces that people feel compelled to defend in what they perceived to be a "not-theirs", adversarial environment. And when people feel the need to defend their own shit, they become aggressive.

That's one of the minor reasons why I quit driving: even I, an utterly placid man who really, REALLY doesn't care about his car all that much, feel slightly more agitated and more on the defensive when I hit the road. I don't like the feeling of becoming more aggressive and stupid.