When I’m driving and someone is doing something strange on
the road, it is virtually guaranteed that they are talking on the cell
phone. I have seen people driving far
too slowly on the highway, weaving across lanes, and braking quickly to avoid
hitting a car in front of them. Earlier
this summer, I had to lean on my horn as someone talking on the phone
blissfully drove within a few feet of my car exiting a parking lot while
talking animatedly to a friend.
It shouldn’t be surprising that talking on the cell phone
(even with a hands-free device) impairs your driving ability. Driving is a moderately difficult thing to
do. You have to watch out for other
drivers, for bicycles, for pedestrians, and you have to keep control of a large
and heavy vehicle. You need to
anticipate what is going to happen, because your car will not stop or change
direction immediately.
Having a conversation also requires some effort. You have to listen to what someone else is
saying. You have to think about what you
are going to say next. You have to keep
in mind what you want to say when your conversation partner is finishing up.
Psychologists have spent years demonstrating that performing
two tasks at once almost always makes you worse at both tasks than you would be
if you did the two tasks alone. In
particular, doing effortful things like driving are made worse by doing
something else at the same time.
A paper by Jason Watson and David Strayer in the August,
2010 issue of Psychonomic Bulletin and
Review suggests that some people may not be affected by doing two tasks at
once. They had 200 people perform a
realistic driving simulation in a lab.
They had to drive on a simulated highway behind a car that would sometimes
step on the brakes. They had to follow
the car at an appropriate distance and brake when necessary. Sometimes, people did the driving alone. At other times, they did it while performing
a complicated task while talking on a hands-free cell phone device. This second complex task is called the OSPAN,
and it involves remembering words and doing math problems. People also did the OSPAN without driving.
Almost everyone in the experiment was worse at both driving
and the OSPAN when they did them together compared to when they did them
alone. However, they found 5 people
whose performance on the two tasks was completely unimpaired when they did them
together. That is, these people did just
as well when driving and doing the OSPAN as when they were just driving. These people were all ones who had done quite
well in the driving task alone, so it wasn’t just that they were distracted by
something else when they were driving, and then were distracted again when they
had to do the OSPAN.
Watson and Strayer called these people supertaskers, and they did some statistical analyses to show that
there were more than you would expect just by chance.
Before you go trying this at home, though, there are a few
reasons to want to treat these results with some care.
First, let’s assume that about 2.5% of the population really
can do two things at once without suffering on either task. That still means that there is a 97.5% chance
that you are not one of them. So, you
should still assume that talking on the cell phone makes you worse at driving.
Second, you are the worst judge of your own
performance. Most people recognize that
other people’s driving is made worse by talking on the cell phone, but still
believe that their own performance is not.
There are a few reasons for that.
For one, the difficulties you have doing two things at once also make it
less likely that you will notice your own driving errors. For another, most of the errors you make when
driving are (thankfully) not catastrophic.
So, you may not notice that you were a little to close to the car in
front of you or that you braked a little too later. It is only when a series of things go wrong
that you end up in an accident, and at that point it is too late.
Third, there is some reason to treat the results of this
study with some caution. In this
experiment, people were tested in one session.
That means that 2.5% of the people in this study demonstrated
“supertasking.” That is, these people
did well on both tasks. But, without
bringing these people back a few times, we don’t know where they are
“supertaskers.” So, we don’t know
whether they will always be good at both tasks.
Maybe there are circumstances that lead people to perform well, but they
affect different people at different times.
If we brought all 200 people from this study to the lab a few times, it
is possible that about 2.5% of people will perform well when given two tasks to
do at once, but it would be a different 2.5% of the people each time.
Ultimately, it is worth cutting back on the amount of time
you spend on the cell phone while driving.
Even if there are supertaskers and you happen to be one, you set a
better example for everyone else by paying attention to the road.
