Do Car Bumper Stickers Signal Driver Aggression?

Shankar Vedantam of the Washington Post has an interesting piece on a recent Journal of Applied Social Psychology study by Colorado State University social psychologist William Szlemko that correlates bumper stickers on cars — including stickers that signify peace and other seemingly benign messages — with elevated levels of driver aggression. We excerpt Vedantam’s piece below.

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Watch out for cars with bumper stickers.

That’s the surprising conclusion of a recent study by Colorado State University social psychologist William Szlemko. Drivers of cars with bumper stickers, window decals, personalized license plates and other “territorial markers” not only get mad when someone cuts in their lane or is slow to respond to a changed traffic light, but they are far more likely than those who do not personalize their cars to use their vehicles to express rage — by honking, tailgating and other aggressive behavior.

It does not seem to matter whether the messages on the stickers are about peace and love — “Visualize World Peace,” “My Kid Is an Honor Student” — or angry and in your face — “Don’t Mess With Texas,” “My Kid Beat Up Your Honor Student.”

Hey, you clown! This ain’t funny! Aggressive driving might be responsible for up to two-thirds of all U.S. traffic accidents that involve injuries.

Szlemko and his colleagues at Fort Collins found that people who personalize their cars acknowledge that they are aggressive drivers, but usually do not realize that they are reporting much higher levels of aggression than people whose cars do not have visible markers on their vehicles.

Drivers who do not personalize their cars get angry, too, Szlemko and his colleagues concluded in a paper they recently published in the Journal of Applied Social Psychology, but they don’t act out their anger. They fume, mentally call the other driver a jerk, and move on.

“The more markers a car has, the more aggressively the person tends to drive when provoked,” Szlemko said. “Just the presence of territory markers predicts the tendency to be an aggressive driver.”

The key to the phenomenon apparently lies in the idea of territoriality. Drivers with road rage tend to think of public streets and highways as “my street” and “my lane” — in other words, they think they “own the road.”

Why would bumper stickers predict which people are likely to view public roadways as private property?

Social scientists such as Szlemko say that people carry around three kinds of territorial spaces in their heads. One is personal territory — like a home, or a bedroom. The second kind involves space that is temporarily yours — an office cubicle or a gym locker. The third kind is public territory: park benches, walking trails — and roads.

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For the rest of the piece, click here.