Here's a scenario that should be familiar: You're driving along on the highway. Suddenly, without signaling, a massive SUV comes barreling into your lane from the right, forcing you to jam on the brakes and swerve out of the way to avoid a collision. "Worthless piece of %$#@," you yell to this person you don't know (and who can't hear you) before embarking on a quest to teach them a lesson by tailgating them for the next two miles.

In his 1950 short, Motor Mania, Goofy plays Mr. Walker, a law abiding, kind, and courteous citizen—until he steps into his car. All of a sudden Mr. Walker undergoes a Hydian transformation, becoming Mr. Wheeler, a reckless, selfish, "uncontrollable monster." Wrapped in his "personal armor," Mr. Wheeler screams at other motorists, flies off the handle at the slightest perceived provocation, and through it all still considers himself a good driver.

You are Goofy. You are. But why?

Rageaholics Anonymous

Part of the problem has to do with what psychologists call "deindividuation." Coined around the same time Motor Mania was released, the word indicates a loss of self-awareness and along with it, individual accountability. This can happen in a number of different scenarios and contexts, but anonymity (perceived or real) is always a key ingredient.

One well known study, conducted by psychologist Philip Zimbardo in 1970, took a group of female students at NYU, gave them hoods, put them in the dark, assigned them numbers to replace their names, and then asked them to administer shocks to other students. Zimbardo found that compared to subjects who were just wearing name tags, the hooded participants were willing to administer twice the level of electric shock (no one was actually shocked) to others.

Then there's Ed Diener's famous Halloween Candy experiment in which 1,300 trick-or-treating children were given the opportunity to steal candy and money under a number of different controlled scenarios. The kids stole significantly more candy and money when they were a part of a larger group and weren't asked for their names and addresses at the house. The least amount of stealing happened when trick-or-treaters were solo and were asked for identifying information.

While anonymity doesn't automatically beget antisocial actions, it can lead to more aggressive, less inhibited behavior, says psychologist Jamie Madigan. Those conditions? Being part of a group and not being held responsible for your actions. Like, for example, online games, message boards, and chat rooms, says Madigan, who focuses on the psychology of video games. Anonymity, he says, "leaves people more open and susceptible to suggestion or to being influenced by real or perceived conditions."

And cars, it turns out, work pretty much the same way as an identity-masking hood. In his book, Traffic: Why We Drive the Way We Do, journalist Tom Vanderbilt points out that while driving, people are surrounded by others (part of a group), and yet they're also cut off (anonymous), enclosed in steel and glass shells.

In fact, when you look at Zimbardo's description of conditions that contribute to a sense of deindividuation, it basically reads like a list of everyday road conditions. “Anonymity, diffused responsibility, group activity, altered temporal perspective, emotional arousal, and sensory overload are some of the input variables that can generate deindividuated reactions,” he says in the International Encyclopedia of Psychiatry, Psychology, Psychoanalysis, and Neurology.

To make matters worse, (as Vanderbilt points out), cars and modern freeways render drivers mute. That makes them mad. Behind the wheel, you're stripped of the ability to communicate in all but the most primitive, non-nuanced ways (honking, hand gestures, and light flashing), while your identity gets reduced down to a brand of vehicle. (Seriously, is there anything worse than the driver of a late model BMW 3 Series?). When you combine all of these factors, you have a really potent recipe for rage and aggressive behavior.

Emotional Non-Intelligence

Remember that unobservant and/or entitled asshole driving the SUV? It turns out our assessments of other drivers, along with their motivations, are also often painfully simplistic or flat out wrong. Maybe the SUV driver had to quickly swerve to avoid a piece of road debris you didn't see. Maybe you were the asshole, riding in his blind spot and being too preoccupied to notice that he did in fact use his blinker.

These possibilities don't register while driving because we make snap judgements by consulting our emotions instead of our logic. You were mad, and therefore the SUV driver is an jerk. End of story. It's what behavioral economists call the affect heuristic. These gut reactions enable us to make quick decisions when needed, but they're also the reason you don't like that shifty-looking dude in the copy room and hate all cyclists.

So if driving and traffic prey upon our irrationality and provide us a near perfect laboratory to exercise vile human behavior, is there anything we can do to keep from turning into a bunch of Mr. Wheelers? Well, not driving obviously helps. But there's another solution: Add a passenger.

Passengers rarely seem to get as worked up about things as drivers. Occasionally, they may even challenge a driver's sense of moral outrage and provide a healthy dose of shame and objectivity. "Studies that have examined the brain activity of drivers and passengers as they engaged in simulated driving have shown that different neural regions are activated in drivers and passengers," Vanderbilt writes. "They are, in effect, different people." And when you consider that solo drivers tend to drive more aggressively, the casual carpool may be both a money saver and a great form of road therapy.