Steps in Problem Solving
1. Preparation: Find and frame
problem
2. Production: Develop good
problem-solving strategies
(subgoals, algorithms,
heuristics)
3. Evaluate solutions
4. Rethink and redefine problems
and solutions over time
Heuristics vs. algorithms
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Heuristics: general problem solving strategies
that are often useful but not always effective
(in football: control line of scrimmage, avoid
turnovers, in chess: control center of board.)
Algorithms: step by step procedures
guaranteed to solve a specific problem
(recipe to bake a cake, formula to solve for
area of triangle)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Examples of Heuristics
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1. Means-end analysis: breaking problem down
into series of sub-problems.
2. Analogies: using past experience as model for
current problem-solving
Research on use of analogies (past experience)
contradictory.
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fixation
- using a prior strategy only
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functional fixedness
- fixated on usual functions
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
When is past experience harmful?
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Dunker (1945) Make a lamp problem.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Thinking—Five Key Barriers to
Problem Solving
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2. Functional Fixedness:
thinking of an object as
only functioning in its
usual way
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Can you use these supplies
to mount the candle on the
wall so that it can be lit in a
normal way without toppling
over?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Thinking—Five Key Barriers to
Problem Solving
(Functional Fixedness Continued)
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To overcome
functional fixedness,
think of the matchbox,
tacks, and candle all
functioning in new
ways.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
When is past experience harmful?
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Mental set: retaining a old successful
problem-solving procedure even though it is
not effective in its current context. Water jar
example here!
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Experimental testing for mental set: Luchin’s (1942)
water jar problem:
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Thinking—Five Key Barriers to
Problem Solving
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1. Mental Set:
persistence in using
strategies that have
worked in the past
Using no more than four
lines, can you connect all
nine dots without lifting
your pencil from the
paper?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Thinking—Five Key Barriers to
Problem Solving (Mental Sets Continued)

To overcome
a mental set
you must
“think outside
the box”—
literally!
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
When is past experience helpful to problem solving?
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1. Gick & Holyoak (1980) studies of problems
solving with and without past experience
2. Chi’s (1985) studies of expertise and
problem solving
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Problem solving in Physics professors vs. students:
Problem categorization
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Problem solving in Physics professors vs. students:
Problem categorization
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Problem solving in Physics professors vs. students:
Problem categorization
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Framing Effects in Problem solving
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Imagine that the U.S. is preparing for the outbreak of an
unusual…
disease which is expected to kill 600 people. Two alternative
programs
have been proposed. Assume that the exact scientific estimate
of the consequences of the program is as follows:
If Program A is adopted, 200 people will be saved.
If Program B is adopted, there is a 1/3 probability that 600
people will be saved and a 2/3 probability that no people will
be saved.
Which of the two programs would you favor?
Imagine the identical situation with the following choices:
If program C is adopted, 400 people will die.
If program D is adopted, there is a 1/3 probability that nobody
will die, and a 2/3
probability that 600 people will die.
Which of the two programs would you favor?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Decision-Making Biases
Confirmation Bias

search only for info that supports our ideas
Hindsight Bias

report falsely that we predicted an outcome
Availability Heuristic

predict probability based on ease of recall
Base-Rate Fallacy
 ignore info about general principles
Representativeness Heuristic

make judgments based on stereotypes
Reasoning

mental activity of transforming information to reach
conclusions
inductive reasoning
- driven by data; bottom-up; specific  general
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deductive reasoning
driven by logic; top-down; general  specific
Syllogistic reasoning: premises – conclusion
Conditional reasoning: if-then statements used draw
conclusions
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Reasoning
Syllogistic reasoning
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Premise: statement assumed to be true for
sake of argument, not necessarily empirically
true

Premise: All boys are athletes
Premise also usually expresses a relationship
between certain concepts, so boys are
related to athletes in that all boys are a
member of the category athletes.
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©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Syllogistic reasoning
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Conclusion: to be valid must be necessitated
by the premises. Must be only possible
conclusion drawn base on relationships
expressed in premises.
Conclusion: a valid conclusion cannot just be
reasonable or plausible based on premises, it
must be necessary.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Syllogistic reasoning
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P1: All boys are athletes
P2: All athletes are muscular
C: All boys are muscular
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Valid: Use Venn Diagrams to determine.
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©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Syllogistic reasoning
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P1: All boys are athletes
P2: All muscular people are athletes
C: All boys are muscular people
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Valid?
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See website for more reasoning problems
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©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Conditional reasoning
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If: antecedent condition
Then: consequent
When the antecedent condition is met, the
consequent will occur (no question about it!)
Observation – what condition is actually
present
Conclusion: (valid or not valid)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Conditional reasoning
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If she has red hair
Then she buys new shoes
Observation: she has red hair (affirming
antecedent)
Conclusion: she buys new shoes (valid?)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
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If she has red hair
Then she buys new shoes
Observation: she has not red hair (denying
the antecedent)
Conclusion: she buys not new shoes (valid?)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
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If she has red hair
Then she buys new shoes
Observation: she buys new shoes (affirming
the consequent)
Conclusion: she has red hair (valid?)
More conditional reasoning problems at my
website.
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
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If she has red hair
Then she buys new shoes
Observation: she buys not new shoes
(denying the consequent)
Conclusion: she has not red hair (valid)
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Wason Selection Task
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Rule: if there is vowel on one side then there is an even
number on the other side of the card
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Abstract reasoning vs. Social contracts reasoning
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Social contracts version of Wason
Selection task
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Language
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What is language: a symbolic rule-based
system of communication shared by a
community
Question: can one person have language?
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Structure of Language
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Phonology - basic phonemes (sounds)
Phoneme :smallest unit of speech or sound
Morphology - rules for word formation
Morpheme: smallest meaningful unit of language
Syntax - rules for combining words to form phrases and
sentences
Semantics - meaning of words and sentences
Pragmatics - use of language
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Note: Grammar includes all these
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Properties of language
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1. Arbitrariness: fundamental units of
language have arbitrary relationship to what
they represent e.g. dog =
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2. Generativity = from a set of finite
fundamental units, infinite meaning is
possible
3. Generational transmission: passed on from
one generation to the next
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©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Properties of language
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4. Displacement: can communicate about
ideas not in here and now
5. Semanticity: meaningfulness drives all
communication
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Studies in Animal Language
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A number of species have been studies:
dolphins, parrots, whales, etc
Most studies have involved nonhuman apes:
Chimpanzees, Gorillas, Bonobos
Why: close relatives of humans, big brains,
highly social
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
History of Ape language studies
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Cross-fostering: raising an ape as a human
baby
1950’s Keith and Cathy Hayes: Viki project,
teaching a chimpanzee to speak. Big
disaster.
Beatrix and Alan Gardner: Washoe project,
teaching an ape sign language
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
History of Ape language studies
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Francine Patterson and
Koko: A gorilla learns sign
language
Herb Terrace and Nim
Chimpsky
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
History of Ape language studies

Sue Savage-Rumbaugh and the bonobo
Kanzi
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
What do apes know about language?
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Some elementary syntax
Some evidence of displacement
100-200 word vocabulary
Use is primarily utilitarian, not for sharing
experience; 90% of Kanzi’s utterances are
requests/commands
About at level 2.5 child
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Language Development
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Prelinguistic Stage:
crying, cooing, and
babbling
Linguistic Stage: singleutterances, telegraphic
speech, and learning the
rules of grammar
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)
Theories of Language Development
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–
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Nature Perspective: language is an inborn
capacity that develops primarily by
maturation
Chomsky’s language acquisition
device (LAD)
Nurture Perspective: language develops
from a complex system of rewards,
punishments, and imitation
©John Wiley & Sons, Inc. 2007
Huffman: Psychology in Action (8e)