Few drive well while yakking on cell phones

A new study from University of Utah psychologists found a small group of people with an extraordinary ability to multitask: Unlike 97.5 percent of those studied, they can safely drive while chatting on a cell phone.

These individuals – described by the researchers as "supertaskers" – constitute only 2.5 percent of the population. They are so named for their ability to successfully do two things at once: in this case, talk on a cell phone while operating a driving simulator without noticeable impairment.

The study, conducted by psychologists Jason Watson and David Strayer, is now in press for publication later this year in the journal Psychonomic Bulletin and Review.

This finding is important not because it shows people can drive well while on the phone – the study confirms that the vast majority cannot – but because it challenges current theories of multitasking. Further research may lead eventually to new understanding of regions of the brain that are responsible for supertaskers' extraordinary performance.

"According to cognitive theory, these individuals ought not to exist," says Watson. "Yet, clearly they do, so we use the supertasker term as a convenient way to describe their exceptional multitasking ability. Given the number of individuals who routinely talk on the phone while driving, one would have hoped that there would be a greater percentage of supertaskers. And while we'd probably all like to think we are the exception to the rule, the odds are overwhelmingly against it. In fact, the odds of being a supertasker are about as good as your chances of flipping a coin and getting five heads in a row."

The researchers assessed the performance of 200 participants over a single task (simulated freeway driving), and again with a second demanding activity added (a cell phone conversation that involved memorizing words and solving math problems). Performance was then measured in four areas—braking reaction time, following distance, memory, and math execution.

As expected, results showed that for the group, performance suffered across the board while driving and talking on a hands-free cell phone.

For those who were not supertaskers and who talked on a cell phone while driving the simulators, it took 20 percent longer to hit the brakes when needed and following distances increased 30 percent as the drivers failed to keep pace with simulated traffic while driving. Memory performance declined 11 percent, and the ability to do math problems fell 3 percent.

However, when supertaskers talked while driving, they displayed no change in their normal braking times, following distances or math ability, and their memory abilities actually improved 3 percent.

The results are in line with Strayer's prior studies showing that driving performance routinely declines under "dual-task conditions" – namely talking on a cell phone while driving – and is comparable to the impairment seen in drunken drivers.