A Silver Lining To Sidewalk Rage

Maia Szalavitz sees one:

While it sounds like an oxymoron, altruistic punishment is basically how social norms get enforced. So when you expel a huffy "Excuse me!" to the rude sidewalk clogger in front of you who has stopped midstride to check his BlackBerry, you're trying to discourage behavior that endangers other members of the society. It's called "altruistic" punishment, because your efforts to protect civility come at personal cost with little chance of personal benefit: you are far more likely to get an obscene gesture or even a punch in the mouth than a thank you.