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some errors of reasoning
CognitiveIllusions
The ArgumentThe Argument
• Perception, memory and “reason” are reliable but not
infallible.
• There are errors of reasoning and sensory illusions to which
all people are prone.
• But if we know about them we can avoid being fooled.
ConceptsConcepts• Cognitive Illusions: “Informal Fallacies” and other errors of
judgment
• Denying the evidence
• Anchoring
• Confirmation bias
• The Rule of Typical Things (“Representativeness Heuristic”)
• Conjunction fallacy
• The Paradox of Choice
• Implicit bias
• How conditionals are falsified
• “Strength” of a proposition: ‘in weakness there is strength’
Real Life Real Life Consequences!Consequences!
Libertarian PaternalismLibertarian Paternalism
Angels of MonsAngels of Mons
Denying the EvidenceDenying the Evidence
Crop CirclesCrop Circles
More crop circlesMore crop circles
Availability ErrorAvailability Error
AnchoringAnchoring• In 5 seconds, please estimate the product of
9 x 8 x…x 1
• 9! = 362,880
• Virtually everyone gives an estimate that’s much too low
• But subjects asked to estimate 1 x 2…x 9 on the average give even lower answers than those asked to estimate 9 x 8 x…x 1
AnchoringAnchoring
Confirmation BiasConfirmation Bias
A D 4 7
We look for evidence that confirms a hypothesis--and tend to ignore data that would falsify it
Hypothesis: If a card has a vowel on one side then it has an even number on the other
How do you determine the most effective means for deciding whether the hypothesis is correct or incorrect?
How do you determine the most effective means for deciding whether the hypothesis is correct or incorrect?
AA DD 44 77
Most subjects thought that only the A and 4 cards needed to be turned over.
Hypothesis: If a card has a vowel on one side then it has an even number on the other.Hypothesis: If a card has a vowel on one side then it has an even number on the other.
AA DD 44 77
22
Hypothesis: If a card has a vowel on one side then it has an even number on the other.Hypothesis: If a card has a vowel on one side then it has an even number on the other.
AA DD 44 77
22 EE
Hypothesis: If a card has a vowel on one side then it has an even number on the other.Hypothesis: If a card has a vowel on one side then it has an even number on the other.
AA DD 44 77
22 66 EE
Hypothesis: If a card has a vowel on one side then it has an even number on the other.Hypothesis: If a card has a vowel on one side then it has an even number on the other.
AA DD 44 77
22 66 EE II
Hypothesis: If a card has a vowel on one side then it has an even number on the other.Hypothesis: If a card has a vowel on one side then it has an even number on the other.
A D 4 7
An evennumber
supports thehypothesis
Turning thiscard is
completelypointless!
A vowelis consistent
with thehypothesis
A vowelfalsifies thehypothesis
conclusively
For future reference . . .For future reference . . .
The hypothesis we were testing was a CONDITIONAL--an if-then statement.
In a conditional the “if” clause is called the antecedent and the “then” clause is called the consequent, e.g.
If a card has a vowel on one side then it has an even number on the other.
A conditional is conclusively shown to be false if its antecedent is true and its consequent is false!
The Paradox of ChoiceThe Paradox of Choice
Student Scores(Spring 2014)
Student Scores(Spring 2014)
• Possible high/low: 91/13
• Schwartz’s results:
– High: 75
– Low: 25
– Average: 50
• Logic students
– High: 81
– Low: 40
– Average: 59
• My score: 27
Is maximizing a good strategy?Is maximizing a good strategy?
• Typically (i.e. not always) satisficers maximize while maximizers fail
• Suppose we want to maximize our utility (happiness, desire-satisfaction)
• + benefit of outcome achieved, e.g. great shoes
• - costs of search and deliberation, e.g. hitting 100 websites and 9 stores looking for the perfect pair of shoes.
• Does the difference between satisfactory and great shoes outweigh the costs of search?
Representativeness Heuristic (stereotyping)
Representativeness Heuristic (stereotyping)
The Linda Problem: Linda is 31, single, outspoken and very bright. She majored in philosophy. As a student she was deeply concerned with issues of discrimination and social justice and also participated in antinuclear demonstrations.
Which is more probable?
–Linda is a bank teller
–Linda is a bank teller and is active in the feminist movement
Bank Tellers Feminist Activists
Bank tellers who are feminist activists
WhereWhere’’s Linda?s Linda?
A and B can’t be more likely than A!A and B can’t be more likely than A!
• Predicting A leaves it open whether it is or isn’t a B too.
• Predicting that it’s an A and B is riskier!
A’s B’s
Things that are both A and B
The Conjunction FallacyThe Conjunction Fallacy
1. Linda is a bank teller and Linda is active in the feminist movement.
2. Linda is a bank teller
(1) can’t be more probable than (2) because it is “stronger,” i.e. conveys more information, than (2)
A conjunction (“and” statement) can never be more probable than one of its conjuncts!
Moral: In weakness there is strength!
Implicit BiasImplicit Bias
• Many cognitive processes that affect behavior are unconscious in nature and are inaccessible to observation by the actor.
• These implicit processes affect perception, influence behavior, and color interpretation of past events.
The Implicit Association TestThe Implicit Association Test
The IAT requires the rapid categorization of various stimulus objects, such that easier pairings (and faster responses) are interpreted as being more strongly associated in memory than more difficult pairings (slower responses).
The Implicit Association TestThe Implicit Association Test
• The IAT “measures the thumbprint of culture on our minds.”
– 88 percent of white people had a pro-white or anti-black implicit bias
– Nearly 83 percent of heterosexuals showed implicit biases for straight people over gays and lesbians
– More than two-thirds of non-Arab, non-Muslim volunteers displayed implicit biases against Arab Muslims.
The Implicit Association TestThe Implicit Association Test
• We all have the thumbprint of culture on our minds
– 48 percent of blacks showed a pro-white or anti-black bias
– 36 percent of Arab Muslims showed an anti-Muslim bias.
– 38 percent of gays and lesbians showed a bias for straight people over homosexuals.
Real World ConsequencesReal World Consequences
• The results of the IAT are confirmed by “real world” tests of biased behavior
• Economists at the Massachusetts Institute of Technology and the University of Chicago recently sent out 5,000 résumés to 1,250 employers who had help-wanted ads…Some applicants were given stereotypically white-sounding names such as Greg; others were given black-sounding names such as Tyrone…Every employer got four résumés: an average white applicant, an average black applicant, a highly skilled white applicant and a highly skilled black applicant.
Employers wanted minorities!Employers wanted minorities!
• Interviews beforehand with human resources managers at many companies in Boston and Chicago had led the economists to believe that black applicants would be more likely to get interview calls.
• Employers said they were hungry for qualified minorities and were aggressively seeking diversity.
Results of the ExperimentResults of the Experiment
• Résumés with white-sounding names triggered 50 percent more callbacks than résumés with black-sounding names.
• High-quality black résumés drew no more calls than the average black résumés.
• Highly skilled candidates with white names got more calls than average white candidates, but lower-skilled candidates with white names got many more callbacks than even highly skilled black applicants.
More resultsMore results• The resume sting operation has been repeatedly with similar
results.
• Recently in France employers were sent identical resumes with applicants identified by either “Franco-French” or “Arab-sounding” names.
– 30% of the Franco-French applicants got interviews.
– Only 5% of the Arabs got interviews.
• In response, a number of firms are now ‘blind-reviewing’ resume, avoiding names and pictures
• When symphony orchestras began auditioning blind women instantly went from just the harpist to 1/3 of the orchestra and has been climbing since
RemediesRemedies• Blind review
– not always possible
– doesn’t eliminate pre-market discrimination
• Equal opportunity regulations
– how can we prove discrimination when the criteria are soft?
• Affirmative action
– what constitutes a reasonable goal?
• Taking philosophy and learning how to go with your head instead of your gut!
"Mind bugs operate without us being conscious of them. They are not special things that happen in our heart because we are evil."
The MoralThe Moral• The following is a false dichotomy:
– Either people (primarily wicked white western males) are consciously discriminating against women, minorities, etc.
– Or women, minorities, etc. get more or less equal treatment.
• We can avoid acting on our implicit biases if we
– recognize that we have them (like recognizing peculiarities of of minds that produce optical illusions) and
– Going with our heads rather than our guts!
Philosophy kills mind-bugs!Philosophy kills mind-bugs!
If we understand the “pecularities of our minds at work” we can factor them out and make correct judgments.
Don’t go with your gut!
