I used to think that the most dangerous thing about bumper stickers was that they make curious drivers inch ever closer to the car in front of them in order to read the things (“He Put the Duh in W,” perhaps, or “At Least the War on the Environment is Going Well,” or “49% Bitch, 51% Sweetheart; Don’t Push It,” or “If There Is a Tourist Season, Why Can’t We Shoot Them?”—for all of which I am indebted to http://www.bumperart.com). But no, bumper stickers pose another danger: drivers who plaster their vehicles with the things are more prone to road rage than drivers who leave their car or truck unadorned.
As scientists led by Paul Bell, Lucy Troup and Bell's student William Szlemko of Colorado State University report in the June issue of the Journal of Applied Social Psychology, it’s a simple matter of territoriality. Researchers have long known that drivers who have a strong sense of personal space while in their vehicle are more likely to be road-ragers, and the more someone plasters his vehicle with bumper stickers and decals the more territorial he feels about the space inside.
As researchers at the American Automobile Association warned way back in 1995:
“Human beings are territorial. As individuals we have a personal space, or territory, which evolved essentially as a defense mechanism—anyone who invades this territory is potentially an aggressor and the time it takes the aggressor to cross this territory enables the defender to prepare to fend off or avoid the attack. This may extend no further than a matter of a few feet or less. . . . The car is an extension of this territory. Indeed, the territory extends for some distance beyond the vehicle, again providing room for the defender to prepare to fend off or avoid the attack. If a vehicle threatens this territory by cutting in, for example, the driver will probably carry out a defensive maneuver. This may be backed up by an attempt to re-establish territory . . . flashing headlights or a blast of the horn are, perhaps, most commonly used for this purpose. However, this may not always succeed in communicating the full depth of our feelings. As it is usually difficult to talk or even shout to the offending driver, other non-verbal communication (offensive gesticulations) may be employed. . . . In some circumstances, the defending driver may wish to go one step further and assert his dominance. Many drivers admit to having chased after a driver to ‘teach him a lesson,’ often pressing him by moving to within inches of his rear bumper. This is comparable to the manner in which a defending animal will chase an attacker out of its territory.”
In 1995 AAA found that road rage had been responsible for 12,610 injuries and 210 deaths in the first six years of the 1990s, and that the number of road-rage incidents was rising 7 percent a year. They’re expected to reach at least 25,000 injuries and 370 deaths this year, with thousands more incidents that stop short of bodily (but not necessarily mental or emotional) injury.
So assuming you can even afford to drive this summer, stay away from cars with bumper stickers. As the Colorado scientists report, people with lots of bumper stickers and decals on their car were 16 percent more likely to succumb to road rage. As Szlemko told Nature magazine, “The number of territory markers predicted road rage better than vehicle value, condition or any of the things that we normally associate with aggressive driving.”And the wording of bumper tickers was irrelevant. Someone who plasters his car with religious stickers such as “1 Cross + 3 Nails = 4 Given” is just as likely to go crazy if you pass him as the guy with “I Support the Right to Arm Bears.” To be safe, consider any and all bumper stickers as synonymous with, “This is my space, and if you get too close an obscene gesture will be the least of your problems.”