Thinking and Deciding

DETERMINANTS AND RELATED PHENOMENA 213
side bias did better on a test of logical syllogisms and the Wason four-card problem
(Chapter 4), a test involving attention to statistical evidence rather than anecdotes, a
measure of efficient hypothesis testing, and a measure of the perception of correlations.
No measure of myside bias correlated with inappropriate extreme confidence
or correct use of Bayes’s theorem in probability judgment (Chapter 6). Subjects low
in myside bias also got better scores on tests of general ability, such as the Scholastic
Achievement Test and the Ravens Progressive Matrices (Chapter 2).
Determinants and related phenomena
Let us now consider some possible determinants of irrational belief persistence.
Beliefs about thinking
General beliefs about thinking itself can play a role. People have their own standards
for thinking, some of which encourage poor thinking. The heuristics that we use to
form our beliefs are maintained by certain explicit beliefs about how thinking should
be conducted — beliefs transmitted through the culture (Baron, 1991; Perkins, Allen,
and Hafner, 1983). People differ in their beliefs about how one should draw conclusions.
Some think that changing one’s mind is a sign of weakness and that a good
thinker is one who is determined, committed, and steadfast. Such people, if they
followed their own standards, would be more likely to persist in beliefs irrationally.
Others believe that good thinkers are open-minded, willing to listen to the other side,
and flexible. Most of us probably subscribe somewhat to both of these beliefs. Whatever
our beliefs, most of us desire to be good thinkers, so we try to follow our own
standards.
The last chapter discussed the work of Kuhn on the kinds of standards that people
apply to their own thinking. Other evidence for a role of beliefs about thinking
comes from the study of Stanovich and West (1998), just described. They found that
subjects with less myside bias had beliefs about thinking itself that tended to favor
active open-mindedness. They endorsed items such as, “People should always take
into consideration evidence that goes against their beliefs,” and they disagree with
items such as “Changing your mind is a sign of weakness.”
My own research has found similar results (Baron, 1989). I measured subjects’
beliefs about good thinking, in two different ways. First, subjects were asked how
they thought people ought to respond to challenges to their beliefs. How, for example,
should college students respond when they meet new ideas about religion or
politics? Subjects were classified according to whether or not they thought people
ought to think further, with a view to revising their beliefs if it is warranted. Second,
subjects were asked to give grades (A through F) to hypothetical thinking protocols
for the quality of thinking. Some protocols considered arguments on only one side of
an issue (for example, on the question of whether automobile insurance rates should
be higher for city dwellers than for suburbanites: “My first thought is that each group