Cognition, 8e
Chapter 12
Deductive Reasoning
and Decision Making
Cognition, 8e by Margaret W. Matlin
Chapter 12
Chapter Introduction
dual-process theory
Type 1 processing—fast and automatic
Type 2 processing—slow and controlled
Applies to both deductive reasoning and decision
making.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Deductive Reasoning
The Confirmation Bias
Are human beings rational?
The Standard Wason Selection Task
Demonstration 12.2: The Confirmation Bias—
Wason's Selection Task
Cognition, 8e by Margaret W. Matlin
Chapter 12
Deductive Reasoning
The Confirmation Bias
The Standard Wason Selection Task
confirmation bias
• People tend to try to confirm or support a
hypothesis rather than try to disprove it.
• In other words, people are eager to affirm
the antecedent, but reluctant to deny the
consequent by searching for
counterexamples.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Deductive Reasoning
The Confirmation Bias
Concrete Versions of the Wason
Selection Task
replace numbers and letters with concrete
situations from everyday life
People perform much better when the task is
concrete, familiar, and realistic.
Griggs and Cox (1982)—drinking age example
Performance improved when task implies a
social contract.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Deductive Reasoning
The Confirmation Bias
Applications in Medicine
People seek confirming evidence when selfdiagnosing disorders (e.g., insomnia).
Both medical students and psychiatrists tend
to select information consistent with their
original diagnosis rather than investigate
information that might be consistent with
another diagnosis.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Kahneman and Tversky
• proposed that a small number of heuristics
guide human decision making
• The same strategies that normally guide us
toward the correct decision may sometimes
lead us astray.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Representativeness Heuristic
representativeness heuristic
• People judge that a sample is likely if it is
similar to the population from which the
sample was selected.
• People believe that random-looking
outcomes are more likely than orderly
outcomes.
• This heuristic is so persuasive that people
often ignore important statistical information
that they should consider.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Representativeness Heuristic
Sample Size and Representativeness
hospital babies example
A large sample is statistically more likely than
a small sample to reflect the true proportions
in a population.
small-sample fallacy—assume a small sample
will be representative of the population from
which it was selected
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Representativeness Heuristic
Base Rate and Representativeness
Demonstration 12.3: Base Rates and
Representativeness—Tom W
base rate—how often an item occurs in the
population
base-rate fallacy—emphasize
representativeness and underemphasize
important information about base rates
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Representativeness Heuristic
The Conjunction Fallacy and
Representativeness
Demonstration 12.4: Tversky and Kahneman
• "Linda is a bank teller and a feminist."
• students with different levels of statistical
sophistication
• rank statements in terms of probability
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Representativeness Heuristic
The Conjunction Fallacy and
Representativeness
conjunction rule—The probability of the
conjunction of two events cannot be larger
than the probability of either of its constituent
events.
conjunction fallacy—when people judge the
probability of the conjunction of two events to
be greater than the probability of a constituent
event
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Availability Heuristic
availability heuristic—estimate frequency or
probability in terms of how easy it is to think of
relevant examples
only accurate when availability is correlated
with true, objective frequency
can be distorted by recency and familiarity
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Availability Heuristic
Recency and Availability
• Memory is better for more recent items.
• Recent items are more available.
• People judge recent items to be more likely
than they really are.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Availability Heuristic
Recency and Availability
MacLeod and Campbell (1992)
• When people were encouraged to recall
pleasant events from their past, they later
judge pleasant events to be more likely in
their future.
• When people were encouraged to recall
unpleasant events, they later judged
unpleasant events to be more likely.
• implications for psychotherapy
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Availability Heuristic
Familiarity and Availability
Brown and colleagues
population estimates for various countries
points of view shown by the media
People need to use critical thinking and shift to
Type 2 processing.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Availability Heuristic
The Recognition Heuristic
When comparing the relative frequency of two
categories, if people recognize one category
and not the other, they conclude that the
recognized category has the higher frequency.
This strategy generally leads to an accurate
decision.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Anchoring and Adjustment
Heuristic
Demonstration 12.5
When making an estimate, people begin with
a first approximation (anchor) and then make
adjustments to that number on the basis of
additional information.
People rely too heavily on the anchor, and
their adjustments are too small; over-influence
of current hypotheses or beliefs, top-down
processing
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Anchoring and Adjustment
Heuristic
Research on the Anchoring and
Adjustment Heuristic
Demonstration 12.5: Multiplication
If the first number was large, the estimates
were higher than if the first number was
small.
single-digit numbers anchored the
estimates far too low
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Anchoring and Adjustment
Heuristic
Research on the Anchoring and
Adjustment Heuristic
• operates even when anchor is obviously
arbitrary or impossibly extreme
• operates for both novices and experts
• anchor may restrict the search for relevant
information in memory
• applications in everyday life: courtroom
sentences
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Framing Effect
framing effect—the outcome of a decision
can be influenced by:
1) the background context of the choice
2) the way in which a question is worded
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Framing Effect
The Wording of a Question and the
Framing Effect
People are distracted by surface structure of
the questions.
The exact wording of a question can have a
major effect on the answers.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Framing Effect
The Wording of a Question and the
Framing Effect
Tversky and Kahneman (1981)—lives
saved/lives lost study (Demonstration 12.8)
• "lives saved" question led to more "risk
averse" choices
• "lives lost" question led to more "risk
taking" choices
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Framing Effect
The Wording of a Question and the
Framing Effect
prospect theory
1. When dealing with possible gains (for
example, lives saved), people tend to
avoid risks.
2. When dealing with possible losses (for
example, lives lost), people tend to seek
risks.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
General Studies on Overconfidence
• occurs in a variety of situations
• own decisions vs. statistically observable
measurements
• variety of personal skills
• individual differences
• cross-cultural differences
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Overconfidence in Political Decision
Making
sexual scandals
international conflict
failure to think systematically about the risks
involved
Each side tends to overestimate its own
chances of success.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Overconfidence in Political Decision
Making
Politicians are often overconfident that their
data are accurate.
crystal-ball technique—imagine a completely
accurate crystal ball indicates that your
hypothesis is incorrect
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Overconfidence About Completing
Projects on Time
planning fallacy
• underestimate the amount of time (or
money) required to complete a project
• estimate the task will be relatively easy to
complete
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Overconfidence About Completing
Projects on Time
Possible Explanations
• optimistic scenario
• failure to consider potential problems
• memory for similar tasks
• over-estimate future free time
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Reasons for Overconfidence
1. People are often unaware that their knowledge
is based on very tenuous and uncertain
assumptions and on information from unreliable
or inappropriate sources.
2. Examples that confirm our hypotheses are
readily available, whereas we resist searching
for counterexamples.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Reasons for Overconfidence
3. People have difficulty recalling the other
possible hypotheses, and decision making
depends on memory. If you cannot recall the
competing hypotheses, you will be overly
confident about the hypothesis you have
endorsed.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
Reasons for Overconfidence
4. Even if people manage to recall the other
possible hypotheses, they do not treat them
seriously.
5. Researchers do not educate the public about
the overconfidence problem. As a result, we
typically do not pause and ask ourselves, ‘‘Am I
relying only on Type 1 thinking? I need to
switch over to Type 2 thinking!’’
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
In Depth: Overconfidence About
Decisions
my-side bias—overconfidence that one's own
view is correct in a confrontational situation; often
results in conflict; cannot even consider the
possibility that their opponent's position may be at
least partially correct
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Hindsight Bias
hindsight—judgments about events that
already happened in the past
hindsight bias—judging an event as
inevitable, after the event has already
happened; overconfidence that we could have
predicted the outcome in advance
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Hindsight Bias
Research About the Hindsight Bias
Carli (1999)—judgments about people;
Barbara/Jack study
happy vs. tragic ending
Both groups are confident that they could
have predicted the ending.
Memory errors are consistent with the
outcome.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
The Hindsight Bias
Research About the Hindsight Bias
(continued)
political events
business decisions
Explanations for the Hindsight Bias
anchoring and adjustment
misremembering past events
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Current Status of Heuristics and
Decision Making
Kahneman's heuristic approach may be too
pessimistic
Harris and colleagues—People make fairly
realistic judgments about future events.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Current Status of Heuristics and
Decision Making
Girgerenzer and colleagues
• People are not perfectly rational decision
makers, however people can do relatively
well when they are given a fair chance.
• ecological rationality—People create a
wide variety of heuristics to help them make
useful, adaptive decisions in the real world.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Current Status of Heuristics and
Decision Making
Girgerenzer and colleagues
• default heuristic—If there is a default
option, then people will choose it.
• People bring world knowledge into the
research laboratory.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Current Status of Heuristics and
Decision Making
Both Kahneman's and Gigerenzer's
approaches suggest that decision-making
heuristics generally serve us well in the
real world.
We can become more effective decision
makers by realizing the limitations of these
important strategies.
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Individual Differences: DecisionMaking Style and Psychological WellBeing
Maximizers—tend to examine as many options as
possible (maximizing decision-making style);
may lead to "choice overload"
Satisficers—tend to settle for something that is
satisfactory (satisficing decision-making style)
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Individual Differences: DecisionMaking Style and Psychological WellBeing
Schwartz and coauthors (2002)—
Demonstration 12.9
• maximizer/satisficer scale and several other
measures
• students, healthcare professionals, people
waiting in a train station
Cognition, 8e by Margaret W. Matlin
Chapter 12
Decision Making
Individual Differences: DecisionMaking Style and Psychological WellBeing
Schwartz and coauthors (2002) (continued)
• Maximizers tended to experience more
regret following a choice than satisficers.
• Maximizers tended to experience more
depressive symptoms than satisficers.
• More choices don't necessarily make a
person happier.
Cognition, 8e by Margaret W. Matlin
Chapter 12