Patricia Ellison-Potter, a researcher who now works for the National Highway Traffic Safety Administration, once conducted a series of experiments examining the effects of anonymity on road rage.

Drivers of cars with tinted windows, Ellison-Potter found, were more likely to engage in aggressive behavior on the road.

In another experiment, using a driving simulator, Ellison-Potter and her colleagues asked people to drive a route on which they encountered jaywalkers, slow vehicles and traffic congestion. There were nine situations in which a driver could hit a pedestrian, seven opportunities to run a red light and 116 potential collisions with other vehicles.

Ellison-Potter instructed some volunteers to imagine they were driving in a convertible with the top down - where they would be more visible to others - while other volunteers were told to imagine they were driving in a convertible with the top up - where they would have more anonymity.

As part of the virtual experience, Ellison-Potter also had some drivers see “banners” and “billboards” with aggressive slogans such as “I’m out of estrogen and I have a gun,” and neutral signs such as “Dave’s Dry Cleaners.”

Drivers were seven times more likely to hit pedestrians in the virtual world when they had a sense of anonymity and were the target of aggressive messages.