When people face an uncertain situation, they
don’t carefully evaluate the information or look up relevant statistics.
Instead, their decisions depend on a long list of mental shortcuts,
which often lead them to make foolish decisions. These shortcuts aren’t a
faster way of doing the math; they’re a way of skipping the math
altogether. Asked about the bat and the ball, we forget our arithmetic
lessons and instead default to the answer that requires the least mental
effort.
Although Kahneman is now widely recognized as one of the most
influential psychologists of the twentieth century, his work was
dismissed for years.
Kahneman recounts
how one eminent American philosopher, after hearing about his research,
quickly turned away, saying, “I am not interested in the psychology of
stupidity.”
The philosopher, it turns out, got it backward. A
new study in the
Journal of Personality and Social Psychology
led by Richard West at James Madison University and Keith Stanovich at
the University of Toronto suggests that, in many instances, smarter
people are
more vulnerable to these thinking errors. Although we
assume that intelligence is a buffer against bias—that’s why those with
higher S.A.T. scores think they are less prone to these universal
thinking mistakes—it can actually be a subtle curse.
West and his colleagues began by giving four hundred and eighty-two
undergraduates a questionnaire featuring a variety of classic bias
problems. Here’s a example:
In a lake, there is a patch of lily pads. Every day, the patch doubles
in size. If it takes 48 days for the patch to cover the entire lake, how
long would it take for the patch to cover half of the lake?
Your first response is probably to take a shortcut, and to divide the
final answer by half. That leads you to twenty-four days. But that’s
wrong. The correct solution is forty-seven days.
West also gave a puzzle that measured subjects’ vulnerability to
something called “anchoring bias,” which Kahneman and Tversky had
demonstrated in the nineteen-seventies. Subjects were first asked if the
tallest redwood tree in the world was more than X feet, with X ranging
from eighty-five to a thousand feet. Then the students were asked to
estimate the height of the tallest redwood tree in the world. Students
exposed to a small “anchor”—like eighty-five feet—guessed, on average,
that the tallest tree in the world was only a hundred and eighteen feet.
Given an anchor of a thousand feet, their estimates increased
seven-fold.
But West and colleagues weren’t simply interested in reconfirming the
known biases of the human mind. Rather, they wanted to understand how
these biases correlated with human intelligence. As a result, they
interspersed their tests of bias with various cognitive measurements,
including the S.A.T. and the
Need for Cognition Scale, which measures “the tendency for an individual to engage in and enjoy thinking.”
The results were quite disturbing. For one thing, self-awareness was
not particularly useful: as the scientists note, “people who were aware
of their own biases were not better able to overcome them.” This finding
wouldn’t surprise Kahneman, who admits in “Thinking, Fast and Slow”
that his decades of groundbreaking research have failed to significantly
improve his own mental performance. “My intuitive thinking is just as
prone to overconfidence, extreme predictions, and the planning
fallacy”—a tendency to underestimate how long it will take to complete a
task—“as it was before I made a study of these issues,” he writes.
Perhaps our most dangerous bias is that we naturally assume that
everyone else is more susceptible to thinking errors, a tendency known
as the “bias blind spot.” This “meta-bias” is rooted in our ability to
spot systematic mistakes in the decisions of others—we excel at noticing
the flaws of friends—and inability to spot those same mistakes in
ourselves. Although the bias blind spot itself isn’t a new concept,
West’s latest paper demonstrates that it applies to every single bias
under consideration, from anchoring to so-called “framing effects.” In
each instance, we readily forgive our own minds but look harshly upon
the minds of other people.
And here’s the upsetting punch line: intelligence seems to make
things worse. The scientists gave the students four measures of
“cognitive sophistication.” As they report in the paper, all four of the
measures showed positive correlations, “indicating that more
cognitively sophisticated participants showed larger bias blind spots.”
This trend held for many of the specific biases, indicating that smarter
people (at least as measured by S.A.T. scores) and those more likely to
engage in deliberation were slightly more vulnerable to common mental
mistakes. Education also isn’t a savior; as Kahneman and Shane Frederick
first noted many years ago, more than fifty per cent of students at
Harvard, Princeton, and M.I.T. gave the incorrect answer to the
bat-and-ball question.
What explains this result? One provocative hypothesis is that the
bias blind spot arises because of a mismatch between how we evaluate
others and how we evaluate ourselves. When considering the irrational
choices of a stranger, for instance, we are forced to rely on behavioral
information; we see their biases from the outside, which allows us to
glimpse their systematic thinking errors. However, when assessing our
own bad choices, we tend to engage in elaborate introspection. We
scrutinize our motivations and search for relevant reasons; we lament
our mistakes to therapists and ruminate on the beliefs that led us
astray.
The problem with this introspective approach is that the driving
forces behind biases—the root causes of our irrationality—are largely
unconscious, which means they remain invisible to self-analysis and
impermeable to intelligence. In fact, introspection can actually
compound the error, blinding us to those primal processes responsible
for many of our everyday failings. We spin eloquent stories, but these
stories miss the point. The more we attempt to know ourselves, the less
we actually understand.
Drawing by James Stevenson.
Note: This article has been modified to include mention of Shane Frederick.
