Invitation to Psychology

Chapter 7 Thinking and Intelligence 235

Exaggerating the Improbable (and

Minimizing the Probable) LO 7.5

One common bias is the inclination to exagger-

ate the probability of rare events. This bias helps

explain why so many people enter lotteries and

buy disaster insurance, and why some irrational

fears persist. As we discuss in Chapter 9, evolution

has equipped us to fear certain natural dangers,

such as snakes. However, in modern life, many

of these dangers are no longer much of a threat;

the risk of a renegade rattler sinking its fangs into

you in Chicago or Atlanta is pretty low! Yet the

fear lingers on, so we overestimate the danger.

Evolution has also given us brains that are ter-

rific at responding to an immediate threat, real

or imagined. Unfortunately, our brains did not

evolve to become alarmed by serious future threats

that do not pose much danger right now, such as

global warming (Gilbert, 2006).

When judging probabilities, people are

strongly influenced by the affect heuristic: the

tendency to consult their emotions (affect) when

judging the “goodness” or “badness” of a situation

instead of judging it objectively (Slovic & Peters,

2006; Slovic et al., 2002). Emotions can often help

us make decisions by narrowing our options or

by allowing us to act quickly in an ambiguous or

dangerous situation. But emotions can also mis-

lead us by preventing us from accurately assess-

ing risk. One unusual field study looked at how

people in France responded to a “mad cow” crisis

that occurred several years ago. (Mad cow disease

affects the brain and can be contracted by eating

meat from contaminated cows.) Whenever news-

paper articles reported the dangers of “mad cow

disease,” beef consumption fell during the fol-

lowing month. But when news articles, reporting

affect heuristic The

tendency to consult

one’s emotions instead of

estimating probabilities

objectively.

You are about to learn...

• some biases in reasoning that impair the ability
to think rationally and critically.

• why people worry more about vivid but rare
disasters than about dangers that are far more
likely.

• how the way a decision is framed affects the
choices people make.

• why people often value fairness above rational
self-interest.

• why people need to justify the time, money, or
effort they invest in an action.

Barriers to reasoning

rationally

Although most people have the capacity to think
logically, reason dialectically, and make judg-
ments reflectively, it is abundantly clear that
they do not always
do so. One obstacle
is the need to be
right; if your self-
esteem depends on
winning arguments,
you will find it hard
to listen with an
open mind to com-
peting views. Other obstacles include limited
information and a lack of time to reflect care-
fully. But human thought processes are also
tripped up by many predictable, systematic
biases and errors. Psychologists have studied
dozens of them (Kahneman, 2003, 2011). Here
we describe just a few.

Recite & Review

Recite: State out loud what you know about formal and informal reasoning problems, dialectical

reasoning, and prereflective, quasi-reflective, and reflective judgment.

Review: Next, reread this section.

Now be reasonable and take this Quick Quiz:

1. Yvonne is arguing with Henrietta about whether real estate is a better investment than stocks.
   “You can’t convince me,” says Yvonne. “I just know I’m right.” Yvonne needs training in
   __ reasoning.


2. Seymour thinks the media have a liberal political bias, and Sophie thinks they are too con-
   servative. “Well,” says Seymour, “I have my truth and you have yours. It’s purely subjective.”
   Which of King and Kitchener’s types of thinking describes Seymour’s statement?
   Answers:

Study and Review at MyPsychLab

quasi-reflective 2. dialectical1.

About Why We Don’t

Always Think Critically

Thinking

CriTiCally