I'm not talking about sticking your head in
fMRI scanner, which, so far as anybody can tell, is perfectly safe.
(Unless you happen to have a pacemaker or pieces of shrapnel in your
head, in which case you might want to give the whole procedure a miss).
No, I'm talking about what happens to people
when they read about studies of brain imaging.
Every 29 seconds or so, some scientist publishes a new study using
brain imaging. And some magazine editor gets very excited. Aha, look at
the cool color pictures! Look how the brain "lights up" when people look at
pictures of Hilary versus Obama. This is your brain on crack, and
this is what your brain looks like during orgasm.
There's no denying that the pictures look
cool. But do they actually tell us anything? Sometimes they do, but
often they don't.
Either way, when we look at such pictures
(or even just think about them), our brains start to melt. A just-published study from Yale University
shows that the average person's psychological IQ -- by which I mean not
their overall intelligence, but rather their capacity to think straight
about psychology -- drops about 20 points the minute they hear the
words "frontal lobes". In the Yale study, three groups of subjects --
ordinary joes, undergrads taking a neuroscience course, and experts --
read brief discussions of psychological phenomena, and then had to say
whether the explanations made sense or not.
To take a typical example, subjects might
read about a phenomenon known as "the curse of knowledge" (something I discussed recently at klugetheblog.com).
As the experimenters describe it, the curse of knowledge is about
believing that if you know something, you expect that most other people
will, too:
Researchers
created a list of facts that about 50% of people knew. Subjects in this
experiment read the list of facts and had to say which ones they knew.
They then had to judge what percentage of other people would know those
facts. ..... If the subjects did know a fact, they [presumed] that an
inaccurately large percentage of others would know it, too. For
example, if a subject already knew that Hartford was the capital of
Connecticut, that subject might say that 80% of people would know this,
even though the correct answer is 50%.
Why should that be the case? Subjects in the
Yale experiment had to sift through explanations like these, deciding
which were good explanations, and which were poor explanations:
1. The
researchers claim that this '' curse '' happens because subjects have
trouble switching their point of view to consider what someone else
might know, mistakenly projecting their own knowledge onto others.
2. The
researchers claim that this '' curse' happens because subjects make
more mistakes when they have to judge the knowledge of others. People
are much better at judging what they themselves know.
3. Brainscans indicate
that this '' curse '' happens because of the
frontallobe brain circuitry known to be involved in self-knowledge.
Subjects have trouble switching their point of view to consider what
someone
else might know, mistakenly projecting their own knowledge onto others.
4. Brainscans indicate
that this ''curse ''happens because of the frontal lobe brain circuitry
known to be
involved in self-knowledge. Subjects make
more mistakes when they have to judge the knowledge of others. People
are much better at judging what they themselves know.
Subjects in the Yale study were pretty good
at distinguishing
between #1 and #2. (#1 is a good explanation, since it tells us *why*
the curse of knowledge might exit; #2 is empty.) But (except for the
experts) people were terrible
at distinguishing #3 from #4, and in fact manythought that #4
(which in reality is no
more illuminating than #2) was nearly as good as #1.
As the study's authors -- Deena Wiesberg
and
her colleagues -- put it ,"It is not the mere presence of verbiage
about neuroscience that encourages people to think more favorably of an
explanation. Rather, neuroscience information seems to have the
specific effect of making bad explanations look significantly more
satisfying than they would without neuroscience."
Why are we such suckers?
Gary
Marcus is the author of the new book
Kluge: The Haphazard Construction of the Human
Mind, an in-depth look at the fallacies of human
thought.
Loading comments…
Posted March 22, 2008 | 07:51 PM (EST)