My Cell Phone, My Death

I've been interested for some time in the hidden cognitive costs of talking on cell phones. I've found that almost nobody believes that their driving is impaired while chatting on a mobile, but the evidence is absolutely unshakable. It's been going on for years. I happened upon an article in Chance magazine from 1997, where the authors provided very strong statistical evidence that individual crashes were closely linked to cell phone use, but it took David Strayer and the University of Utah to actually measure reaction times and prove that cell phone use effectively turned 20-somethings into senior citizens while driving. It's purely a cognitive thing; using a hands-free set doesn't make any difference. Talking with a passenger doesn't have the same effect. Strayer's research shows that using a cell phone degrades change detection.

Of almost equal interest is the refusal of most people to believe the research. We're not conscious of much that happens within us, despite the belief that we are. I find that my usability class students are uniformly indignant at the suggestion that merely talking on a cell compromises their ability to drive. The attention blindness, however, it works, that envelops us during that time is not consciously evident to us. Hence, we remain oblivious to the danger.

The 1997 Chance article by Redelmeier and Tibshirani (cited by Strayer) detailed the meticulous analysis the authors did to conclude that individual car phone users were some four times more likely to crash compared to non-users during crashes. But they also examined why, if the chances soar so dramatically, that the overall accident rate hasn't also risen dramatically, which might by itself make cell users give up the devices while driving. They found that although cell phone use would indeed boost an individual's chances for an accident, the chance of an accident at all is so low that in the aggregate cell phone use doesn't raise the population's rate much at all. Cell phone calls are generally of short duration, which further reduces the overall effect.