Rational and Irrational Thoughts…

Rational and Irrational Thoughts…:

“One cause of dysrationalia is that people tend to be cognitive misers,
meaning that they take the easy way out when trying to solve problems,
often leading to solutions that are wrong. 

Another cause of dysrationalia is the mindware gap, which occurs when
people lack the specific knowledge, rules and strategies needed to think

Tests do exist that can measure dysrationalia, and they should be given
more often to pick up the deficiencies that IQ tests miss. 

shallow processing can lead physicians to choose less effective medical
treatments, can cause people to fail to adequately assess risks in their
environment, can lead to the misuse of information in legal
proceedings, and can make parents resist vaccinating their children. 

Decades of research in cognitive psychology have suggested two causes
of dysrationalia. One is a processing problem, the other a content
problem. Much is known about both of them.

The Case of the Cognitive Miser

When approaching a problem, we can choose from any of several
cognitive mechanisms. Some mechanisms have great computational power,
letting us solve many problems with great accuracy, but they are slow,
require much concentration and can interfere with other cognitive tasks.
Others are comparatively low in computational power, but they are fast,
require little concentration and do not interfere with other ongoing
cognition. Humans are cognitive misers because our basic tendency is to
default to the processing mechanisms that require less computational
effort, even when they are less accurate.

Are you a cognitive miser? Consider the following problem, taken from
the work of Hector Levesque, a computer scientist at the University of
Toronto. Try to answer it yourself before reading the solution:

1. Jack is looking at Anne, but
Anne is looking at George. Jack is married, but George is not. Is a
married person looking at an unmarried person?

  • A) Yes
  • B) No
  • C) Cannot be determined

More than 80 percent of people choose C. But the correct answer is A.
Here is how to think it through logically: Anne is the only person
whose marital status is unknown. You need to consider both
possibilities, either married or unmarried, to determine whether you
have enough information to draw a conclusion. If Anne is married, the
answer is A: she would be the married person who is looking at an
unmarried person (George). If Anne is not married, the answer is still
A: in this case, Jack is the married person, and he is looking at Anne,
the unmarried person. This thought process is called fully disjunctive
reasoning—reasoning that considers all possibilities. The fact that the
problem does not reveal whether Anne is or is not married suggests to
people that they do not have enough information, and they make the
easiest inference © without thinking through all the possibilities.

Most people can carry out fully disjunctive reasoning when they are
explicitly told that it is necessary (as when there is no option like
“cannot be determined” available). But most do not automatically do so,
and the tendency to do so is only weakly correlated with intelligence.

Here is another test of cognitive miserliness, as described by Nobel
Prize–winning psychologist Daniel Kahneman and his colleague Shane

2. A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?

Many people give the first response that comes to mind—10 cents. But
if they thought a little harder, they would realize that this cannot be
right: the bat would then have to cost $1.10, for a total of $1.20. IQ
is no guarantee against this error. Kahneman and Frederick found that
large numbers of highly select university students at the Massachusetts
Institute of Technology, Princeton and Harvard were cognitive misers,
just like the rest of us, when given this and similar problems.

Another characteristic of cognitive misers is the “myside” bias—the
tendency to reason from an egocentric perspective. In a 2008 study my
colleague Richard West of James Madison University and I presented a
group of subjects with the following thought problem:

3. Imagine that the U.S.
Department of Transportation has found that a particular German car is
eight times more likely than a typical family car to kill occupants of
another car in a crash. The federal government is considering restricting
sale and use of this German car. Please answer the following two
questions: Do you think sales of the German car should be banned in the
U.S.? Do you think the German car should be banned from being driven on
American streets?

Then we presented a different group of subjects with the thought
problem stated a different way—more in line with the true data from the
Department of Transportation at the time, which had found an increased
risk of fatalities not in a German car but in an American one:

Imagine that the Department of
Transportation has found that the Ford Explorer is eight times more
likely than a typical family car to kill occupants of another car in a
crash. The German government is considering restricting sale or use of
the Ford Explorer. Please answer the following two questions: Do you
think sales of the Ford Explorer should be banned in Germany? Do you
think the Ford Explorer should be banned from being driven on German

Among the American subjects we tested, we found considerable support
for banning the car when it was a German car being banned for American
use: 78.4 percent thought car sales should be banned, and 73.7 percent
thought the car should be kept off the streets. But for the subjects for
whom the question was stated as whether an American car should be
banned in Germany, there was a statistically significant difference:
only 51.4 percent thought car sales should be banned, and just 39.2
percent thought the car should be kept off German streets, even though
the car in question was presented as having exactly the same poor safety

This study illustrates our tendency to evaluate a situation from our
own perspective. We weigh evidence and make moral judgments with a
myside bias that often leads to dysrationalia that is independent of
measured intelligence. The same is true for other tendencies of the
cognitive miser that have been much studied, such as attribute
substitution and conjunction errors; they are at best only slightly
related to intelligence and are poorly captured by conventional
intelligence tests.

The Mindware Gap

The second source of dysrationalia is a content problem. We need to
acquire specific knowledge to think and act rationally.
cognitive scientist David Perkins coined the term “mindware” to refer to
the rules, data, procedures, strategies and other cognitive tools
(knowledge of probability, logic and scientific inference) that must be
retrieved from memory to think rationally.
The absence of this knowledge
creates a mindware gap—again, something that is not tested on typical
intelligence tests.

One aspect of mindware is probabilistic thinking, which can be measured. Try to answer the following problem before you read on:

4. Imagine that XYZ viral
syndrome is a serious condition that affects one person in 1,000.
Imagine also that the test to diagnose the disease always indicates
correctly that a person who has the XYZ virus actually has it. Finally,
suppose that this test occasionally misidentifies a healthy individual
as having XYZ. The test has a false-positive rate of 5 percent, meaning
that the test wrongly indicates that the XYZ virus is present in 5
percent of the cases where the person does not have the virus.

Next we choose a person at random and administer the test, and the
person tests positive for XYZ syndrome. Assuming we know nothing else
about that individual’s medical history, what is the probability
(expressed as a percentage ranging from zero to 100) that the individual
really has XYZ?

The most common answer is 95 percent. But that is wrong. People tend
to ignore the first part of the setup, which states that only one person
in 1,000 will actually have XYZ syndrome. If the other 999 (who do not
have the disease) are tested, the 5 percent false-positive rate means
that approximately 50 of them (0.05 times 999) will be told they have
XYZ. Thus, for every 51 patients who test positive for XYZ, only one
will actually have it. Because of the relatively low base rate of the
disease and the relatively high false-positive rate, most people who
test positive for XYZ syndrome will not have it. The answer to the
question, then, is that the probability a person who tests positive for
XYZ syndrome actually has it is one in 51, or approximately 2 percent.

A second aspect of mindware, the ability to think scientifically, is
also missing from standard IQ tests, but it, too, can be readily

5. An experiment is conducted
to test the efficacy of a new medical treatment. Picture a 2 x 2 matrix
that summarizes the results as follows:

As you can see, 200 patients were given the experimental treatment and
improved; 75 were given the treatment and did not improve; 50 were not
given the treatment and improved; and 15 were not given the treatment
and did not improve. Before reading ahead, answer this question with a
yes or no: Was the treatment effective?

Most people will say yes. They focus on the large number of patients
(200) in whom treatment led to improvement and on the fact that of those
who received treatment, more patients improved (200) than failed to
improve (75). Because the probability of improvement (200 out of 275
treated, or 200/275 = 0.727) seems high, people tend to believe the
treatment works. But this reflects an error in scientific thinking: an
inability to consider the control group, something that (disturbingly)
even physicians are often guilty of. In the control group, improvement
occurred even when the treatment was not given. The probability of
improvement with no treatment (50 out of 65 not treated, or 50/65 =
0.769) is even higher than the probability of improvement with
treatment, meaning that the treatment being tested can be judged to be
completely ineffective.

Another mindware problem relates to hypothesis testing. This, too, is
rarely tested on IQ tests, even though it can be reliably measured, as
Peter C. Wason of University College London showed. Try to solve the
following puzzle, called the four-card selection task, before reading

6. As seen in the diagram, four
cards are sitting on a table. Each card has a letter on one side and a
number on the other. Two cards are letter-side up, and two of the cards
are number-side up. The rule to be tested is this: for these four cards,
if a card has a vowel on its letter side, it has an even number on its
number side. Your task is to decide which card or cards must be turned
over to find out whether the rule is true or false. Indicate which cards
must be turned over.

Most people get the answer wrong, and it has been devilishly hard to
figure out why. About half of them say you should pick A and 8: a vowel
to see if there is an even number on its reverse side and an even number
to see if there is a vowel on its reverse. Another 20 percent choose to
turn over the A card only, and another 20 percent turn over other
incorrect combinations. That means that 90 percent of people get it

Let’s see where people tend to run into trouble. They are okay with
the letter cards: most people correctly choose A. The difficulty is in
the number cards: most people mistakenly choose 8. Why is it wrong to
choose 8? Read the rule again: it says that a vowel must have an even
number on the back, but it says nothing about whether an even number
must have a vowel on the back or what kind of number a consonant must
have. (It is because the rule says nothing about consonants, by the way,
that there is no need to see what is on the back of the K.) So finding a
consonant on the back of the 8 would say nothing about whether the rule
is true or false. In contrast, the 5 card, which most people do not
choose, is essential. The 5 card might have a vowel on the back. And if
it does, the rule would be shown to be false because that would mean
that not all vowels have even numbers on the back. In short, to show
that the rule is not false, the 5 card must be turned over.

When asked to prove something true or false, people tend to focus on
confirming the rule rather than falsifying it. This is why they turn
over the 8 card, to confirm the rule by observing a vowel on the other
side, and the A card, to find the confirming even number. But if they
thought scientifically, they would look for a way to falsify the rule—a
thought pattern that would immediately suggest the relevance of the 5
card (which might contain a disconfirming vowel on the back). Seeking
falsifying evidence is a crucial component of scientific thinking. But
for most people, this bit of mindware must be taught until it becomes
second nature.

Dysrationalia and Intelligence

The modern period of intelligence research was inaugurated by Charles Spearman in a famous paper published in 1904 in the American Journal of Psychology.
Spearman found that performance on one cognitive task tends to
correlate with performance on other cognitive tasks. He termed this
correlation the positive manifold, the belief that all cognitive skills
will show substantial correlations with one another. This belief has
dominated the field ever since.

Yet as research in my lab and elsewhere has shown, rational thinking
can be surprisingly dissociated from intelligence. Individuals with high
IQs are no less likely to be cognitive misers than those with lower
In a Levesque problem, for instance (the “Jack is looking at Anne,
who is looking at George” problem discussed earlier), high IQ is no
guarantee against the tendency to take the easy way out. No matter what
their IQ, most people need to be told that fully disjunctive reasoning
will be necessary to solve the puzzle, or else they won’t bother to use
Maggie Toplak of York University in Toronto, West and I have shown
that high-IQ people are only slightly more likely to spontaneously adopt
disjunctive reasoning in situations that do not explicitly demand it.

For the second source of dysrationalia, mindware deficits, we would
expect to see some correlation with intelligence because gaps in
mindware often arise from lack of education, and education tends to be
reflected in IQ scores. But the knowledge and thinking styles relevant
to dysrationalia are often not picked up until rather late in life. It
is quite possible for intelligent people to go through school and never
be taught probabilistic thinking, scientific reasoning, and other
measured by the XYZ virus puzzle and the four-card selection
task described earlier.

When rational thinking is correlated with intelligence, the
correlation is usually quite modest. Avoidance of cognitive miserliness
has a correlation with IQ in the range of 0.20 to 0.30 (on the scale of
correlation coefficients that runs from 0 to 1.0). Sufficient mindware
has a similar modest correlation, in the range of 0.25 to 0.35. These
correlations allow for substantial discrepancies between intelligence
and rationality. Intelligence is thus no inoculation against any of the
sources of dysrationalia I have discussed.