| |
Comment on this article
Details
Grand Illusions
September/October
2003
by Bruce Fellman
Frank
Keil isn't interested in how much you know. He's interested in how
much you think you know. Here's
the sort of test he's devised to help him find out: 1. Name the
eighth president. 2. Sketch the plot of A
Christmas Carol. 3. Tell how to make chocolate chip cookies. 4. Explain
the inner mechanism of a flush toilet. 5. But before you begin,
answer this: How well will you do on each question?
Chances
are, after you've measured your expectations against your performance,
you'll find that the flush toilet is where you fell down. Keil
is a psychologist who studies the conceptual tool kit people use
to make sense of the world, and his signal finding -- confirmed
in a wide variety of subjects and published in numerous scientific
papers (most recently in the August issue of Trends
in Cognitive Science) -- is that,
when it comes to their understanding of how things work, people
fool themselves.
| |
Dr.
Spock was wrong. You know less than you think you do.
|
"For
facts, narratives, and procedures, we're actually pretty good
at matching our perceptions of our knowledge with reality,"
notes Keil. "If we rate our knowledge of, say, the plot of
a novel as a 5, that turns out to be an accurate assessment."
But with explanations, there's a disconnect. "Because you
can drive a car or use a computer, you begin to believe you understand
how they work," he says. In other words, knowing that the
gas starts flowing when you step on the accelerator gives you
the feeling that you also know what's happening to the gas inside
the engine. Keil and his former graduate student Leonid Rozenblit
'03PhD have named this phenomenon "the illusion of explanatory
depth."
Keil
has received a special $1.3 million award from the National Institutes
of Health for his research on how people understand the
world around them. He admits his findings may be disconcerting
for those raised on the reassuring words of baby doctor Benjamin
Spock '25, "Relax. You know more than you think you know." But he believes the tendency is pervasive. He has found it in
children and in his graduate students, who thought they knew how
zippers and helicopters worked. (He has also found it in his undergraduate
students, who thought the grad students only flunked the zipper-helicopter
test because of typical grad-student arrogance.)
Keil
thinks there are good reasons for our explanatory illusions. They
serve as a kind of cerebral shorthand, preventing data overload
in our brains. They also give us the mental flexibility to cope
with challenging situations. "We're remarkably good at handling
incredible causal complexity," he explains. "But we're
not detail-crazy mavens who carry annotated blueprints in our
heads. Instead, we use folk science -- everyday, intuitive, and
sketchy concepts that enable us to construct theories on the fly
with just as much detail as we need."
Some
of those theories might, for instance, help us raise children.
You don't need a degree in gastroenterology to take care of a
newborn; you need to figure out when the baby is hungry. In this
sense, Keil says, Dr. Spock was quite right.  |
|