Thinking and Deciding

212 ACTIVELY OPEN-MINDED THINKING
tional crises from the Greek civil war in 1947 to the Yom Kippur war in 1973. Historical
records of decisions were evaluated for several symptoms of defective decision
making, including “gross omissions in surveying alternatives” (inadequate search
for possibilities); “gross omissions in surveying objectives” (inadequate search for
goals); “failure to examine major costs and risks of the preferred choice” (inadequate
search for evidence); and “selective bias in processing information at hand” (biased
interpretation). Experts in international affairs assessed the outcomes, taking into account
the best interests of the United States and (separately) the best interests of the
world. The symptoms of poor decision making correlated with poor outcomes (from
either point of view). It is possible that the judgments of symptoms were influenced
by the judges’ knowledge of the outcome, but the correlations were high, and some
of the crises were quite obscure, so the effect is probably real. Good thinking does
seem to correlate with good outcomes.
Another type of study has examined correlations between measure of actively
open-minded thinking and measures of the ability to solve various problems. Some
of these problems are of the sort given in school, and others are of the sort used
throughout this book to illustrate biases in thinking. I shall suggest that actively
open-minded thinking helps to reduce some of these biases, and these studies provide
first-blush evidence for that suggestion. They show that people who think in a way
that is actively open-minded are better at solving the problems, or less biased.
In one study, Stanovich and West (1998) reported several experiments, involving
the presentation of several tasks to each of hundreds of college students. One task,
the Argument Evaluation Test, measured myside bias in the evaluation of arguments.
Each item began with Dale (a fictitious person) stating an opinion about a social
issue, for example, “The welfare system should be drastically cut back in size.” The
subject indicated agreement or disagreement (to indicate the subject’s side). Dale
than gave a justification, for example, “because welfare recipients take advantage of
the system and buy expensive foods with their food stamps.” A critic then presented
a counterargument, for example, “Ninety-five percent of welfare recipients use their
food stamps to obtain the bare essentials for their families.” Finally, Dale rebuts the
counterargument, for example, “Many people who are on welfare are lazy and don’t
want to work for a living.” The subject then evaluated the strength of the rebuttal on a
four point scale. The subject’s answer was compared to answers given by experts —
philosophy professors at the University of California, Berkeley, and Stanovich and
West. To estimate myside bias, the authors tried to predict the subject’s ratings from
both the expert ratings and the subject’s own opinion about the issue. Myside bias
was defined as a positive effect of the subject’s beliefs. That is, subjects showing
myside bias were those who tended to deviate from the expert ratings in the direction
of their own opinions, rating arguments as better when they agreed with that opinion.
Most subjects showed some myside bias, but some were more biased than others.
The question is whether the less biased subjects do better on other tasks (compared
to the more biased subjects).
This happened for several tasks, but not for all the tasks used. Myside bias may be
a common problem in reasoning, but it isn’t the only problem. Students with less my-