Critical Thinking - Deerfield High School

HW Check IN
Intuition Article WS and pp. 135-144
Next Class
1. Answer the Blue
Sheet Survey Privately
2. The ON the back of Blue
Survey Answer this question:
a. Do you like the Daily
Show with Jon Stewart Show ?
Yes or NO?
b. Then write down how
much of the class would agree
with your answer (a % please)
3. Then Answer Survey on pg.
130 in CP.
Intuition and Common Sense
Video Analysis:
• Take notes over the
key points the 2
scenes address.
• With a partner
discuss how these
two scenes connect
to the Articles you
read on Intuition.
The Limits of Intuition and Common Sense
• We are not passive
recipients of information,
INTERPRET and construct
our social perceptions to fit
our preconceived notions
of how the world works and
– People are basically
willing to infer and judge
by using mental
“shortcuts” and
otherwise not thinking
too much about things.
• People make sense of their
world by fitting it to their
preconceived notions
• Two mind system:
– System one = intuitive,
rooted in personal
experience, imbued with
emotion and interested in
here-and-now situations.
Unconscious mind
• Intuition = rapid
thought that happens
outside of conscious
perceptions, and
beliefs that are more
or less instantaneous
– System two = logic and
deduction, analyzes the
odds and selects the
most rational decision.
Conscious mind.
Handout 1-2 (Blue Survey) :
Predicting Research Outcomes
• Read the research results and respond to the
questions. Also, document whether you are
surprised by the finding.
• How many of you were surprised by the finding?
How many of you checked “not surprising”?
• There’s a problem… for half of you were given a
finding that is opposite what the other half
• We have a tendency to exaggerate our ability to
have foreseen how something would turn out
AFTER learning the outcome.
Hindsight Bias
Tendency to believe that one would •
have foreseen it after the results are
– “Seems like common sense.”
– “The answer was right there and
look how obvious it was.”
– “I knew it all along
EX: Research on low self-esteem or high selfesteem and susceptibility to flattery.
Perception that psychological research
findings merely verify our common-sense
EX: School Shootings
EX: Several weeks after a political election,
voters often exaggerate their ability to have
predicted the election outcome.
EX: Natural Disasters
• After Hurricane Katrina caused massive
flooding in New Orleans in 2005, many
believed that public officials should have
anticipated the problem. After all, studies
of the levee’s vulnerability had been
conducted, demographics indicated that
many residents did not own cars and
were too poor to afford transportation and
lodging out of town, and meteorologists’
assessment of the storm’s severity
predicted the need to put security and
relief supplies in place.
Opinion Exercise
• “I like the Daily Show with
Jon Stewart” Yes? No?
• Estimate the % of people
in class that you believe
share your opinion.
• How many selected yes?
• How many selected no?
• How many overestimated
the number of people in
agreement with them?
False Consensus Effect
• We believe others agree with us
more than they do.
• We spend most of our time with
a biased sample of people,
mostly those who share our
attitudes and habits.
• EX: Jon Stewart
• EX: Conservatives
think more people
support conservative
views than will people
who are liberals.
• EX: You mistakenly
assume that everyone
around you enjoys
listening to country
music like you do.
Confirmation Bias
• We seek out or notice
evidence that will verify
our ideas more eagerly
than we seek evidence
that might refute them
– EX: Stereotypes we hold
– EX: Business managers
are more likely to follow
the successful careers of
those they once hired
than to track the
achievements of those
they rejected.
– EX: Reading newspaper
columnist that agree with
our point of view and
avoiding those who don’t.
Belief Perseverance
• Tendency to cling
to our beliefs in
the face of
contrary evidence.
EX: Thomas believes that rich people are
stuck up. His friend, Elaine, introduces
him to several rich people who are not at
all stuck up. Thomas still believes rich
people are stuck up.
EX: Coaches continue to believe that hot
hands in b-ball exist
– Scoring streaks are often interpreted
as meaningful. A player has a better
chance of making a shot after just
making two or three shots than after
just missing two or three shots.
– Analysis of thousands of shot
sequences finds that a player’s overall
average is the best predictor of what is
likely to happen next.
– Misinterpreting streaks, not
misperceiving them.
EX: Once people have explained to
themselves why they believe that women
or men are naturally superior or that a
child is gifted or learning disabled, they
tend to ignore the evidence that
undermines that belief. Prejudice persists.
Illusory Correlations
• Both belief perseverance and
confirmation bias are results of
people making illusory
correlations (perceived
correlation that does not really
exist) – when we believe there is
a relationship between two
things, we are likely to notice and
recall instance that confirm our
• EX Hot hands in b-ball
• EX: “Of course it rained.
That is because I just
washed my car!”
• EX: As soon as you
switch into a grocery line
that appears to move
faster, the new line slows
down and the old line
speeds up.
• EX: The gambler believes
he can control the dice by
how he throws them – a
hard roll for a big number
and a soft roll for a low
Handout 9-5 (pg 130 in CP)
Fill out survey
Deaths per 100,000
All accidents (37.7) vs. strokes (51.1)
Suicide (10.9) vs. blood poisoning (11.2)
Homicide (5.9) vs. diabetes (24.5)
Motor vehicle accidents (15.3) vs. colorectal cancer (17.8)
Drowning (1.3) vs. leukemia (7.1)
Largest Population
Morocco (34 million) vs. Saudi Arabia (28 million)
Myanmar (47 million) vs. Australia (21 million)
Vietnam (86 million) vs. South Africa (48 million)
Sri Lanka (20 million) vs. Libya (6 million)
Tanzania (38 million) vs. Iraq (28 million)
Highest Crime Rate
Chicago (15.6) vs. Kansas City (26.1)
Las Vegas (11.3) vs. Stockton (14.6)
Miami (13.9) vs. Phoenix (15.0)
Honolulu (1.7) vs. Raleigh (6.0)
New York (6.6) vs. Aurora (9.5)
Handout 9-5
• Quiet cause of death is actually more prevalent
– People perceived the more publicized and easily
pictured cause to be more
common=Representativeness Heuristic
• Less familiar countries have greater populations
but respondents judge those that are familiar to
them to be more populous
• Larger or more familiar cities are judged to have
a higher crime rate.
• Overconfidence – compare the percentage of
questions you answered correctly with your
average confidence level. How many were
more confident than correct?
Representative Heuristic
Judge a person, object, or
event by how similar it is to
what you imagine to be a
typical representative of a
– We think that people who
exhibit certain
characteristics will exhibit
other, related
characteristics. We think
that “like goes with like”
• EX: If I meet someone with a laid back
attitude and long hair, I might assume
they are Californian, whereas someone
who is very polite but rigid may be
assumed to be English.
• EX: People who were told that Linda
majored in philosophy and was a social
activist. Then they ranked the
probability of statements about Linda
– Linda is a bank teller
– Linda is a bank teller and a feminis
• 80% of people rated the
statement “Linda is a bank teller
and a feminist” as more likely
than “Linda is a bank teller”
• This contradicts the fact that the
probability of x is greater than
the probability of x and y cooccurring (when x and y are
independent events)
Overconfidence Effect
• Tendency to
overestimate the
accuracy of one’s
beliefs and judgments.
A result of the selfserving bias.
EX: When American students start college,
only 2% say there is a very good chance they
will drop out permanently or temporarily.
EX: Students are overconfident about how
quickly they can do assignments and write
EX: Following the 1986 Challenger
explosion, Nobel prizewinning physicist
Richard Feynman asked NASA officials what
risk of failure each mission carried. NASA
engineers said about 1 in 100 flights was
likely to experience a catastrophe. NASA
managers put the risk closer to 1 in 100,000.
Some experts speculate that managers’
overconfidence may have contributed to the
Columbia disaster in February 2003.
EX: Planners often exhibit overconfidence in
estimating how quickly and inexpensively
they can do a project.
– Millennium Park was supposed to open in
2000 at a cost of $150 million… It opened
four years late at more than triple that
Overconfidence among Experts
“There is no reason for anyone to have a computer in their home.” (Ken Olson,
president of Digital Equipment Company, 1977)
“Heavierthanair flying machines are impossible.” (Lord Kelvin, British mathematician,
physicist, and president of the British Royal Society, 1895)
“Reagan doesn’t have the presidential look.” (United Artists executive when asked
whether Ronald Reagan should be offered the starring role in the movie The Best
Man, 1964)
“A severe depression like that of 1920–1921 is outside the range of probability.”
(Harvard Economic Society, Weekly Letter, November 16, 1929)
“Impossible!” (Jimmy “The Greek” Snyder when asked whether Cassius Clay could
last six rounds in his upcoming bout with heavyweight champion Sonny Liston, 1964)
“We know on the authority of Moses, that longer ago than six thousand years, the
world did not exist.” (Martin Luther [1483–1546], German leader of the Protestant
“Man will never reach the moon, regardless of all future scientific advances.” (Lee
DeForest, inventor of the vacuum tube, 1957)
“Nuclear powered vacuum cleaners will probably be a reality within 10 years.” (Alex
Lewyt, manufactures of vacuum cleaners, 1955)
Vivid Cases / Availability Heuristic
• People judge the
frequency of an
event by how
easily it is brought
to mind.
EX: Fear of airplane crashes – US
travelers during the 1980s were 26
times more likely to die in a car
crash than on a commercial flight.
EX: Casinos entice us to gamble by
signaling even small wins with bells
and lights – making them vividly
memorable – while keeping big
losses invisible.
EX: Subjects guess that more
people die from guns than asthma,
cancer than stroke, murder than
floods. Yet, in each case they were
EX: Changes from a wrong to right
answer on a test outnumbered
changes from right to wrong 2-to-1.
Frustration with and memory of
correct answers being changed to
wrong answers causes people to
think answer-changing is bad
EX: The one person who won $197
million in the lottery is remembered
more readily than the 328 million
losing tickets that build the jackpot
Availability Heuristic
The media sometimes leads us to have a distorted view of the frequency of certain
events by overexposing us to some events and underexposing us to others?
The FBI classifies crime in the United States into two categories:
– Violent crimes, such as murder, rape, robbery, and assault,
– Property crimes, such as burglary, larceny, or car theft.
• What percentage of crimes would you estimate are violent rather than
property crimes?
• What percentage of accused felons plead insanity? What percentage are
• What percentage of convictions for felony crimes are obtained through trial
instead of plea bargaining?
– In 2006, there were 417,745 violent crimes and 9,983,568 property
crimes. Violent crimes were 12.4 percent of the total of all crimes.
– Less than 1 percent of all accused felons plead insanity and only a
quarter of those are ultimately acquitted.
– Less than 10 percent of convictions for felony crimes are obtained
through a trial; more than 90 percent result from plea bargaining.
However, aided by the news media’s reporting, we tend to overestimate the number
of violent crimes, pleas of insanity, and trials, because they are more available to
• Discovering Psychology: Judgment and
Decision Making
Handout 1-5
• Fill out survey
• By a show of hands, whose estimate was
greater than 1500 miles? Whose estimate
was greater than 30 million people?
• The Mississippi River is actually 2348
miles and the population of Argentina is
more than 40 million.
Anchoring and Adjustment Heuristic / Framing
• Make judgments by starting with
an initial estimate and then adjust it
to yield the final answer. When
people are presented with an
answer to a question, they use that
answer as a reference point. How
an issue is framed can significantly
affect decisions and judgments
• EX: Participants were shown a
number, either 10 or 65. They
were then asked to estimate the
proportion of African nations in
the UN. People who saw a 10
gave an average estimate of
25%. Those who saw a 65 gave
an average estimate of 45%
• EX: What is the best way to
market ground beef- As 25% fat
or 75% lean?
• EX: A surgeon tells someone
that 10% of people die, while
another surgeon tells someone
that 90% survive. Info is same,
but effect is not. The risk seems
greater to those who hear that
10% will die.
• EX: offer regular prices as sale
Anchoring Heuristic  causes problems
when people take surveys
Respondents may be totally ignorant of an issue and often do not want to admit it.
– In one famous study, a third of the people surveyed offered an opinion about a
nonexistent “Public Affairs Act.” Many respondents tell pollsters only what they
think the dominant media want to hear.
– Their tendency to give acceptable rather than honest responses is also evident in
how the gender and race of the interviewer influence results. When interviewed
by Whites, 62 percent of White respondents agreed that “The problems faced by
Blacks were brought on by Blacks themselves.” When interviewed by Blacks,
only 46 percent agreed. When interviewed by a man, 64 percent of women
agreed that “abortion is a private matter that should be left to the woman to
decide without government interference.” When interviewed by a woman, 84
percent of women respondents agreed.
Respondents may be ignorant of the numbers or words used
– A survey of 1255 adults by New York’s American Museum of Natural History and
Louis Harris found:
• 77 percent were interested in plants and trees but only 39 percent were
interested in botany.
• A total of 48 percent were interested in fossils but only 39 percent were
interested in paleontology.
• Of the total sample, only 42 percent were interested in rocks and minerals,
but 53 percent were interested in geology.
Problem Solving Strategies
Changing the Representation of the Problem = many problems can be represented in a
variety of ways, such as verbally, mathematically, or spatially. When you fail to make progress
with your initial representation of a problem, changing your representation.
Insight = sudden and often novel realization of the solution to a problem.
Trial and Error = successive elimination of incorrect solutions until the correct one in found.
Works best when choices are limited.
Algorithms = methodical (step-by-step), logical rule or procedure that guarantees solving a
particular problem.
Heuristics = rule of thumb that help in simplifying and solving problems, although they do not
guarantee a correct solution
a. Availability Heuristic
b. Representative Heuristic
c. Anchoring Heuristic
d. Hill Climbing = moving continually closer to our final goal without ever digressing or going
e. Means-end Analysis = identifying differences that exist between the current state and the
goal state and making changes that will reduce these differences.
• Setting subgoals = breaking a problem into smaller, more manageable pieces, each
of which is easier to solve than the problem as a whole.
f. Working Backward = the search for a solution begins at the goal and works backward
toward the “givens.”
g. Searching for analogies – if you can spot an analogy between problems, you may be able
to use the solution to a previous problem to solve a current one.
Changing the Representation of the Problem
1. Buddhist Monk
Problem –
2. Husbands and
Problem –
3. Six Match
How would you arrange six
matches to form four
equilateral triangles?
1. EX: Jokes and riddles
2. EX: Aha! Experiences
A. Rebuses
B. Chain-Link Problem
C. Wealthy Desert Dweller
D. Story of the Hunter
E. Nail Problem
Jokes and Riddles
The maker doesn’t want it, the buyer doesn’t use it,
and the use doesn’t see it. What is it?
Can you translate the following into a
sentence? 100204180
A coffin
I ought naught to owe for I ate nothing.
What number is next in this series: 10, 4, 3, 11, 15 …?
A. 14 B. 1 C. 17 D. 12
14. When spelled out, each number in the series is
longer than the previous number by one letter.
What is so unusual about the sentence? “Jackdaws
love my big sphinx of quartz.”
What occurs in every minute, twice in every
moment, yet never in a thousand years?
The letter M
How can you physically stand behind your father
while he is standing behind you?
A man left home one morning. He turned
right and ran straight ahead. Then he turned
left. After awhile, he turned left again,
running faster then ever. Then he turned left
once more and decided to go home. In the
distance he could see two masked men waiting
for him. Who were they?
Stand back to back
The umpire and the other team’s catcher
It’s the shortest sentence in the English language that
includes every letter of the alphabet
Something extraordinarily unusual happened on the 6 th
of May, 1978, at 12:34 p.m. What was it?
At that moment, the time and day could be written as
12:34, 5/6/78
Can you translate the following? Y Y U R Y
Y U B I C U R Y Y 4 M E.
Too wise you are. Too wise you be, I see you
are, Too wise for me.
Setting Subgoals
1. Tower of
2. Hobbit and
Working Backward
1. Hobbit and Orcs Problem
Problem Solving Obstacles: Fixation and Mental Set
Fixation – inability to restructure or reorganize problems. Inability to
see a problem from a new perspective.
Mental Set – the tendency to perceive and to approach problems in
certain ways - repeat solutions that have worked in the past. Have
a hard time solving the following problems because you have a wellestablished habit of perception or thought.
– EX: Two grandmasters played five games of chess. Each won
the same number of games and lost the same number of
games. There were no draws in any of the games. How could
this be so?
• Solution: They didn’t play against each other.
– EX: A man who wanted a drink walked into a bar. Before he
could say a word he was knocked unconscious. Why?
• Solution: He walked into an iron bar, not a drinking
Mental Set
Need paper and pencil in solving the following problem:
– Assume that you’re the engineer of a passenger train. At the first
station, 20 passengers get on. At the next station, 5 passengers get off
and 15 get on. At the next station, 10 passengers get off and 12 get on.
At the next station, 7 get off and 10 get on. At the next station, 20
passengers get off and 5 get on. At the next station, 8 passengers get
off and 3 get on.
Write down numbers 1 through 5 to answer the following questions:
How old is the engineer of the train?
How many stations were there?
How many passengers are left on the train?
Altogether, how many passengers have gotten off the train since the first
Altogether, how many passengers have gotten onto the train anywhere
along its route?
We pay attention to only some aspects of information input and ignor wthe
rest. Only that information to which we are attuned is available for
processing toward a solution. We tend to use the specific strategies that
have worked in the past.
Functional Fixedness
• Our tendency to see the
functions of objects as
fixed and unchanging.
The more you use an
object in one way, the
harder it is to see new
uses for it.
• EX: Candle Mounting
• Solution: Have to think of
using the box for more
than it’s normal use.
• EX: a person might
ransack the house for a
screwdriver when a dime
would have turned the
Using these materials, how would you
mount the candle on a bulletin board?
Answers to pp. 133-134 in CP Limits
To Intuition W.S.
1. Hindsight Bias
2. FAE
3. Overconfidence
4. Rep. Heuristic
5. Illusory Correlation
6. Availiability Heuristic
7. Hindsight Bias
8. Anch Heuristic
9. Gamblers Fallacy
10. Sunk Cost
11. Illusory Correlation
12. Framing
13. Overconfidence
14. Hindsight Bias
15. Conf Bias
16. Halo Effect
17. Barnum Effect
18. Anchoring
19. False Con Effect
20. Belief Perserverance
21. Sunk Cost
22. Hindsight Bias
Problem Solving Obstacles: Unnecessary
1. Unnecessary
Constraints - specifying
all the constraints
governing a problem
without assuming any Without lifting your pencil or retracing
constraints that don’t
any line, draw four straight lines that
connect all nine dots
 EX: Nine-Dot