can keep us from reaching a goal. Fixationis an inability to look at a problem from a fresh
perspective, using a prior strategy that may not lead to success. If we’ve solved 10 prob-
lems in a 50-problem set using one rule, we tend to use the same rule to solve the 11th.
This tendency to approach the problem in the same way that has been successful previ-
ously is a type of fixation called mental set.We may get stuck on the 11th problem
because it requires a different rule from the first 10. Another type of fixation that can be
an obstacle to problem solving is called functional fixedness,a failure to use an object in
an unusual way. For example, if people are carrying plastic tablecloths to a picnic area
when it starts to rain, and they get soaked because they aren’t wearing raincoats and don’t
have umbrellas, they are evidencing functional fixedness. They could have used the table-
cloths to protect them from the rain. Using decision-making heuristics when we problem
solve can result in errors in our judgments. Amos Tversky and Nobel prize winner Daniel
Kahneman studied how and why people make illogical choices. They looked at two types
of research. Normative studies ask how we oughtto make decisions, and do not actually
reflect how people make decisions. Descriptive studies look at how decisions are actually
being made. Tversky and Kahneman found we often make erroneous decisions based on
intuition. Under conditions of uncertainty, we often use the availability heuristic,esti-
mating the probability of certain events in terms of how readily they come to mind. For
example, many people who think nothing of taking a ride in a car are afraid to ride in an
airplane because they think it is so dangerous. In fact, riding in an airplane is much safer;
we are far less likely to be injured or die as a result of riding in an airplane. Other errors
in decision making result from using the representative heuristic,a mental shortcut by
which a new situation is judged by how well it matches a stereotypical model or a partic-
ular prototype. Is someone who loves to solve math problems more likely to be a mathe-
matics professor or a high school student? Although many people immediately reply that
it must be the professor, the correct answer to the problem is the high school student. The
total number of high school students is so much greater than the total number of mathe-
matics professors that even if only a small fraction of high school students love to solve
math problems, there will be many more of them than mathematics professors. Framing
refers to the way a problem is posed. How an issue is framed can significantly affect
people’s perceptions, decisions, and judgments. We are more likely to buy a product that
says it is 90% fat-free, than if it says it contains 10% fat. A suggestion can have a power-
ful effect on how we respond to a problem. Kahneman and Tversky asked if the length of
the Mississippi River is longer or shorter than some suggested length, then asked how long
the person thinks the river actually is. When the suggested length was 500 miles, the
length guessed was much smaller than when the suggested length was 5,000 miles. The
anchoring effectis this tendency to be influenced by a suggested reference point, pulling
our response towards that point.Biases
Confirmation biasis a tendency to search for and use information that supports our
preconceptions, and ignore information that refutes our ideas. To lessen this tendency, we
can consider the opposite. Belief perseveranceis a tendency to hold on to a belief after the
basis for the belief is discredited. This is different from belief bias,the tendency for our
preexisting beliefs to distort logical reasoning, making illogical conclusions seem valid or log-
ical conclusions seem invalid. Hindsight biasis a tendency to falsely report, after the event,
that we correctly predicted the outcome of the event. Finally, the overconfidence biasis a
tendency to underestimate the extent to which our judgments are erroneous. For example,
when reading this section dealing with obstacles to problem solving and errors in decision
making, we tend to think that we make these errors less often than most other people.136 ❯ STEP 4. Review the Knowledge You Need to Score High