Where’s the road rage in Berkeley?

According to research cited by Rob Walker in his Consumed column in The New York Times Magazine, “drivers who put bumper stickers and other decorations on their vehicles are 16 percent more likely to engage in road rage” (the peer-reviewed research is behind a paywall here).

If there’s anything that characterizes cars in Berkeley, it’s a higher than usual quotient of bumper stickers.

So where’s the road rage? Or is Berkeley an outlier in this, as in so many other things?