Week 10: Reasoning

Question 1

Reasoning and Decision Making

Answer 1

Judgement:
estimating magnitudes/probabilities of some characteristic

Reasoning: drawing conclusions

Decisions: making choices between alternatives

Forming an opinion on a particular thing

Finding magnitude of certain characteristics

Taking available evidence that we have and concluding

Looking at available alternatives and choosing among them and acting in that certain way

Conclusions help us make decisions

Question 2

Deductive Reasoning

Answer 2

Starts broad principles to make logical predictions about specific cases

Determining whether a conclusion logically follows from premises

Syllogistic reasoning

Two statements called premises

Third statement called conclusion

Categorical syllogism

Describe relation between two categories using. all, no, or some

Do not confuse “validity” with “truth”

Syllogism is valid if conclusion follows logically from its two premises

Truth refers to a relationship that holds in reality

Syllogisms can have validity but not the truth, and can have truth but not validity

Question 3

Deductive

Answer 3

Situations where we start with broad principles and try to make a logical prediction about specific case

General to specific

Remember, don’t confuse validity with truth

Trying to determine if a syllogism is valid

Truth is what we usually think about

Question 4

Categorical Syllogism

Answer 4

All men are mortal. (major premise)

Socrates is a man. (minor premise)
(therefore)

Socrates is mortal. (conclusion)

Question 5

Logic and Eular

Answer 5

Assess syllogistic logic

Have category A represented by a circle, show a relationship with A and B by circle overlap

All A are B

No A are B

Some A are not B, Some A are B

Goal isn’t to find a way that sylllogism is true, but false

False makes it invalid

Question 6

Abstract

Answer 6

All A are B (major)

All C are B (minor) therefore, All A are C (conclusion)

All A are not C in the diagram

True or False (valid)?

Question 7

Concrete

Answer 7

All Liberals are human. (major premise)

All Conservatives are human. (minor premise)
(therefore)

All Liberals are Conservatives. (conclusion)

True or False (valid)?

Misinterpretation: All A are B = All B are A

Biggest error people make is that they feel like they can rearrange the equation

You can’t just flip it around

Question 8

Form vs. Content

Answer 8

All dogs are animals. (major premise)

Some animals are pets. (minor premise)
(therefore)

Some dogs are pets. (conclusion)

True or False (valid)?

Dog category is independent from pet circle so syllogen is false

Don’t focus on content, focus on form of diagram

Using sharks make it easier to conceptualize

Belief bias: if content pushes you towards one interpretation, makes it hard to evaluate it logically

Question 9

Reasoning Error

Answer 9

Belief bias (Henle, 1962): The tendency to think that a syllogism is valid if its conclusions are believable

Therefore, beware of syllogism’s conclusions that are true or agree with your beliefs

All of the students are tired

Some tired people are irritable

Some of the students are irritable

Atmosphere effect (Woodsworth & Sells, 1935): global impression or feel of the premises (e.g., same form)

All + All = All ?

All birds are mammals
All mammals sleep
All mammals are birds

Confirmation bias: the tendency to selectively look for information that conforms to our hypothesis and overlook information that argues against it

Question 10

Reasoning Error

Answer 10

Some of the students are irritable is incorrect based on diagram

Atmosphere effect: idea that if the premises give a general feeling of particular form so that you have all As or Bs or Cs, that sort of gives the impression that it must be true

All + all = all

Since all mammals are not birds

Tendency that we have to prove that something is true due to expectation

What we want to do in logic and generally approaching things and we try to find ways that something is untrue

Question 11

Conditional Syllogisms

Answer 11

A logical determination of whether the evidence supports, refutes, or is irrelevant to the stated relationship

Conditional clause (premise 1) – antecedent (if clause)

consequent (then clause)

Evidence (premise 2)

Conclusion?
Psyc 221
Psyc 221

First premise is the (if then) part

Second premise is the evidence support, refutes or is irrelevant to the first premise

Then you have to determine if you can reach some type of conclusion

Modus Ponens (97%)
Modus Tollens (60%)

The only time that you can come up with a valid conclusions is if you are affirming antiselent or denying the consequent

Question 12

Example

Answer 12

Raining (antecedent)

Domique gets wet (consequent)

Evidence: it is raining

Conclusion: therefore, dominque gets wet (modus ponens)

Therefore its not raining (modus tollens)

Tricky since someone could just dump a bucket of water on her

Question 13

Example 2

Answer 13

If i live in vancity

Then i live in BC

Evidence: i live in vancity
Conclusion: therefore, i live in BC

Or i do not live in BC, therefore, i do not live in vancouver

Or i live in BC, therefore, i do not live in vancouver

I dont live in vancouver, but i do live in BC

Question 14

Wason Four Card Problem (1966)

Answer 14

To determine which cards needed to be flipped over to test the rule

One side had number and other had letter

If vowel then it was an even number

7 would go against the rule

E and 7 would need to be flipped

People have the most difficulty with this

Becomes easier when stated in terms that you can actually think of

Concrete terms will help

Agrees with the schema, a permission schema which agrees with the rules of society

Drinking is allowed to certain individuals in society

16 yr old would invalidate the question, drinking beer would also

Falsification principle:to test a rule, you must look for situations that falsify the rule
* Most participants fail to do this
* When problem is stated in concrete everyday terms, correct responses greatly increase

Question 15

Wason Four Card Problem (1966)

Answer 15

To determine which cards needed to be flipped over to test the rule

One side had number and other had letter

If vowel then it was an even number

7 would go against the rule

E and 7 would need to be flipped

People have the most difficulty with this

Becomes easier when stated in terms that you can actually think of

Concrete terms will help

Agrees with the schema, a permission schema which agrees with the rules of society

Drinking is allowed to certain individuals in society

16 yr old would invalidate the question, drinking beer would also

Falsification principle:to test a rule, you must look for situations that falsify the rule
* Most participants fail to do this
* When problem is stated in concrete everyday terms, correct responses greatly increase

Permission schema: if A is satisfied, B can be carried out
* Used in the concrete versions * People are familiar with rules

Question 16

Inductive Reasoning

Answer 16

Reasoning that is based on observation
* Generalizing from observations of specific cases to more general conclusion
* Reaching conclusions from evidence
* Conclusions are suggested only, with varying
degrees of certainty.
* Strength of argument
* Representativeness of observations * Number of observations
* Quality of evidence

Used to make scientific discoveries
* Hypotheses and general conclusions
* Usedineverydaylife
* Make a prediction about what will happen based on observation about what has happened in the past

Question 17

Inductive Reasoning

Answer 17

This is the opposite of deductive
Particular observation and determining the general conclusion
Based on evidence
We are trying to figure out what is being suggested
We still want as much certainty as possible and there are things that will strengthen the argument
You want a representatives sample
E.g., all crows are black in particular city
But if you only have the crows in one city, you cannot generalize all crows to the ones you have seen
Need higher amount of observations, the stronger the conclusion will be
Is there multiple sources that point to your conclusion
Such as articles with similar observations

Essentially what is used in science
Constantly looking at certain situations, taking these data points and taking hypothesis and determining general conclusions
Everyday, you have these expectations in the world that things will behave the way you expect, these are the inductions

Question 18

Accounts of Reasoning/Decision Making

Answer 18

Normative: how things ought to go; what people should do

Descriptive: how things are; what people actually do (do)

Heuristic: a short cut; a strategy that risks error to gain efficiency (speed)

Algorithm: a guaranteed route to an outcome, which may be more tedious and effortful

Normative is how things should work in society

Descriptive is what people actually do

Heuristic is a short cut that allows us to reach a decision faster

Algorithm is sitting down and actually thinking about what we actually need but is very tedious

Question 19

Kahneman and Tversky

Answer 19

pioneered the research on judgment under uncertainty
* emphasized the heuristics we use to process evidence and make judgments
* early work done at Hebrew University of Jerusalem

This work started in the 70s at University of Jearusalm
Proposed theory about decision making called prospect theory
Largely done in collab with Tversky
We typically rely on heuristics since we can’t get all the information and even if we could, it would take forever

Question 20

Representative Heuristic

Answer 20

assume that each member of a category is representative of that category (like the prototype?), and has all its traits
* also assume the reverse—if something has a lot of the traits of a category, it probably belongs to that category
* be willing to draw conclusions from a quite small sample: “seen one, seen ‘em all”

Question 21

Representative Heuristic

Answer 21

Argued that when we think about members of categories, we make the assumption that every member is like everyone else in the group
We also make the opposite as if something has alot of the traits of the category, it may be apart of it
If you have a situation where you are seeing something, you have a lot of info of that object since you are assuming that objects category therefore you know all the information about that item
Coin flip example: coin is random, assuming that this is random event and there are 2 possibilities, when things are random, we expect them to change
If you flip a coin 8 times, any of these 3 possibilities are equal due to chance
Each throw is independent

Gamblers Fallacy: feel like random events, the next thing should be a particular outcome
E.g., flipping a coin 4 times and 3 times it landed on heads, bet on last one, most will bet for a tails
People will think tails is more likely even though this isn’t true

Question 22

Kahneman and Tversky (1973)

Answer 22

Talked to a bunch of students as samples in different groups
1 group: given a bunch of majors that they may be pursuing, what probability will students be in each category
Were given a prompt about a person
Asked questions about his similarity to other grads, likely a grad student, and a personality sketch of highschool and likelihood of being a student
More likely to be seen as comp sci or engineering student, likelihood highest as that as well
This proved that people were judging, people assumed his characteristics to people who were probably inclined with those majors
Even happened in the final group, even though things may have changed, people still said that he was more likely to be a comp sci/engineering student since he was similar to them
His test carried a lot of weight into the future
E.g., linda being judged as a feminist accountant doesn’t make sense since all accountants have the same category

This is the conjunction fallacy: 60% of being accountant 20% feminist, 12% of being feminist accountant
Probaility of conjoinment of 2 events is the multiplication of the two probabilities
Hospital birthrates: probabilities of which gender is born more
Large vs. small
10 births vs. 100 births
Any given day, fluctuations can happen so 10 is better and much more likely

Question 23

Kahneman and Tversky (1973)

Answer 23

Likelihood judgments closely mirrored the similarity judgments rather than base rate
* How likely is it that Tom is a comp. sci. student versus humanities student?
* 95% pick comp. sci.
* base rate estimations by other subjects had humanities as 3 times more likely
* Even when based on projective tests that are unreliable, and things change from high school to grad. school

Question 24

English

Answer 24

More r words or words with r as third letter?
Twice as many words with third r
Why do people think first one is right?
Fairly easy to generate words with r and harder to generate words with third r
Hence why we use availability heuristic

Question 25

Availability Heuristic

Answer 25

scan quickly through memory seeking relevant instances
* if instances come quickly to mind, they are likely to be frequent in experience
* availability or accessibility in memory serves as a proxy for frequency in experience
* but the organization of memory can create biases

Scan through memory to see how often this particular event has happened
Use as proxy to say it must be more like;y
The more likely something is rehearsed, better chance of being in LTM
Salience, emotionality of an event
Organize in particular way

Question 26

Slovic, Fischhoff & Lichtenstein (1976)

Answer 26

Subjects asked to estimate frequency of various causes of death.

Homicide Drowning Asthma Asthma Appendicitis Appendicitis Auto-train crash Botulism Tornado Pregnancy

Students in the US
Gave people a bunch of potential causes of death and asked to estimate of how many people die
Per 200 million US
First 2: hugely overestimated from tornado
Last 2: underestimated probability
Due to not hearing it as often
Tornado being on news, boy dying from asthma is not on news
These come to mind more, so we overestimate them

Question 27

Hindsight Bias

Answer 27

hindsight is 20/20”
* the “knew it all along” effect
* looking at a situation retrospectively (after the fact), we saw all the signs leading up to this particular outcome
– going on 3rd (or 4th) and 1 in football
– knowing the outcome of an experiment before it is conducted
– knowing a relationship would fall apart

20/20
Idea that you know the outcome of the situation, it is easy to see the outcome occurring
E.g., football fan, team going 3rd and 1 in football
Before the play, it would be 50/50
If they mess it up, they were stupid
When people tell you the results of the experiment, not uncommon that people will say “obviously”

Bystander effect: diffusion of responsibility
Knowing that a relationship will fall apart, as saying “i could see that coming”

Question 28

Anchoring

Answer 28

people are influenced toward a possible anchor value, even if they should know better
* Prelec & Ariely (2006) – MIT students bid on auction items (told price was last 2 digits of Soc. Sec. #)
– 80-99 paid $26, 00-19 paid $9 for trackball
* Annoying sounds – paid either 90 or 10 cents
– Would take 73 or 33 cents to hear it again

People get influenced into believing something
Prelec and Areily:
Bunch of items for sale and said that cost was the last 2 digits of SS number
Could be $1 or $90
Asked what the max price would be for item
Willing to pay 3x more for same item
Only difference was where they started
Paid users either 90 or 10 cents
Asked if they were willing to do it again
10 cent group was willing to do it 33 cents

Question 29

Class Example

Answer 29

If given 65, say 45
If given 10, say 25
Actual answer was 54/56 so 96%
1 - 8 multiplication -> 512
8 - 1 multiplication -> 2250
This is the anchoring effect: actual answer is over 40k

Question 30

Decision Making

Answer 30

Reasoning/choosing among alternatives * What clothes to wear
* Who to date/marry
* What school to attend
* Even relatively simple decisions are cognitively demanding
* Donders – ~100ms to decide left of right * Posner & Boies(1971)

We do it all the time
When you have these decisions, a lot of them feel really difficult
You have to think about them to make them

Question 31

Posner & Boies (1971)

Answer 31

• Used a dual task technique
• secondary task measures resource demands orsparecapacity(likeathermometer)ofthe primary task at various points
• primary task = letter matching (Aa, AA, AB)
• secondary task = turn off tone on some trials; short RT = low resources in primary task

Duel task technique
Two things at the same time
Idea that the secondary task will basically let you know how resource demanding the first source was
How quickly they could do secondary task
If quickly, means they had a lot of resources
If resources were being allocated to resource task, it would take longer and cause errors
Measured how long it took to turn off tone

Question 32

Capacity Decision

Answer 32

When first letter came up and tone came up same time, people were able to turn it off faster
If it was inbetweem, then rt went up
At second letter, got slower
At key, rt was high but not as high

Question 33

Process Account

Answer 33

Task
1. wait
2. warning
3. first letter
4. delay
5. second letter

Process
1. none?
2. alerting
3. LTM retrieval
4. WM rehearsal
5. a) LTM retrieval
b) trace matching
c) decision (response choice)
d) motor output

Prior to trial, we don’t know whats going on
Triggers system to be ready to respond
LTM retrieval is automatic
The delay is due to WM rehearsal
Even if you find a match, you still keep on going because it would take longer to make a decision to every letter rather than making one decision at the end

Question 34

Decision Making

Answer 34

each decision has costs (taking us farther from our goals) and benefits (moving us toward our goals; providing our values)
* we must weight the costs against the benefits
* goal of making decision to maximize utility

Every particular situation, making one decision will have a cost associated with it
This decision will also have benefits though
People might do a cost-benefit analysis

Question 35

Expected Utility

Answer 35

expected utility = (Probability of an outcome) X (Utility of that outcome)
* Assumption: People are rational
* If they have all relevant information, they will make a decision that results in the maximum expected utility

Evaluation of risks
What you will get out of a situation is going to be the product of how likely a particular outcome is X how much that outcome means to you
Requires us to have good estimates of these concepts so you have the relevant information about probability of outcome and how valuable that outcome is

Advertising (likelood) for lottery tickets
Office pools for lottery tickets, talkin to others
Serotonin release when thinking about if you won
(these are the utility), you think about how good the situation is
Expected utility goes up, likelihood goes down, makes seem like a better deal than it is

Question 36

Lottery Example

Answer 36

lottery ticket = $2
* likelihood of winning = 1 out of 14,000,000
* prize = $4,000,000
* expected utility = (1/14M) X ($4M) = $0.29
* therefore, you are giving away 7 times what
you can expect to receive each time!

Question 37

Decision Making

Answer 37

Decisions depend on how choices are presented
* Opt-in procedure
* Active step to be organ donor
* Opt-out procedure
* Organ donor unless request not to be
* Status quo bias
* The tendency to do nothing when faced
with making a decision * Framing of alternatives

Depend on how choices are presented
Organ donation - various ways that this can be put towards people
Filling out form to opt in for donation
Some countries are fixed organ donors unless requested not to
Status quo bias: we have a bias to do nothing
Companies keep giving deals as you won’t leave since you are already apart of the company and you have to do work to switch
Other companies will give other deals to entice you to join them

Question 38

Framing

Answer 38

Assume yourself richer by $300 than you are today. You must choose between
– a sure gain of $100
– a 50% chance to gain $200 or gain nothing
* Assume yourself richer by $500 than you are today. You must choose between
– a sure loss of $100
– a 50% chance to lose nothing or lose $200

People choose different things according to how they are phrased
If you are going to be loosing something, you will throw the dice and hope that you will not loose much
As you are gaining something, people don’t wanna loose what they are gaining

Question 39

More Framing

Answer 39

Imagine that Canada is preparing for the outbreak of a new disease, which is expected to kill 600 people
* Two alternatives have been suggested in labwork
A: 200 people saved
B: 1/3 probability that all 600 people will be saved, but a 2/3 probability that none of the 600 will be saved

Contrast this with these alternatives
A: 400 will die
B: 1/3 probability that no one will die but a 2/3 that all of the 600 will die

Question 40

Framing

Answer 40

phrasing of the decision affects our choice * framing in terms of losses tends to make
us risk-seeking
* framing in terms of gains makes us risk- averse

Question 41

Decision Making

Answer 41

Emotions affect decisions
* Expected emotions
* Emotions that people predict that they will feel concerning an outcome
* Explain risk aversion
* People inaccurately predict their emotions
* Overestimate negative emotions

Emotions affect decisions
People are not good at predicting on how they will feel about a situation
Kermer and colleagues
Gave people $5 and flipped coin, 50% you will gain 5 and 50% you will loose 3
First tell how you will feel if you win or lose
Lose, down by 4 points, win, go up 2 points (happiness)
Prediction is twice is bad of negative feeling if i lose
After filler test, people who lost were down by a point and people who won went up a point
So winning does make you happy but the difference seems to be about the same
Not what people estimated

Question 42

Emotions

Answer 42

Incidental emotions: Emotions that are not specifically related to decision-making
* May be related to one’s general disposition or personality, some recent experience, or one’s general environment or surroundings
* Can affect one’s overall decision making processes

Emotions that are from other factors can effect DM
Study done and simple task was given
A highlighter, how much are you willing to sell it for
Sad, disgust and neutral
How much are you willing to buy it for
Neutral: buy low, sell high
Disgust: buy low, sell low (just wanna stay constant)
Sad: buy high, sell low (just want change)

Question 43

Unconscious Bias

Answer 43

Prejudice
* Implicit Association Test (IAT)

Response to pictures
White or black person
Or bad or good
Face and words
Idea is that there is an unconscious assocaitation of the words and face

Question 44

Green, Carney, Pallin, Ngo, Raymond, Iezzoni & Banaji (2007)

Answer 44

Measured explicit attitudes
* Measure IAT
* Read a vignette about Mr. Thompson a 50- year-old male presenting to the emergency department with chest pain and an EKG suggestive of anterior myocardial infarction. It is stated that primary angioplasty is not an option and no absolute contraindications to thrombolysis are evident.

Study in hospitals in Boston, went to medical residents
Questionaire on their explicit attitudes on black and white people
Given a prompt

Question 45

Results

Answer 45

No explicit bias reported
* Diagnosis of Coronary Artery Disease:
Very likely - 29.8% white vs. 40.1% black
* Were not anymore likely to treat blacks with Thrombolysis

No difference in explicit bias
Low on IAT, they were more likely prescribe thrombolysis to black people
High on IAT, more likely to give to white people
Predominant patients were black but still showed bias

Question 46

Context

Answer 46

Number of response options
* Redelmeirer & Shafir (1995) – found that physicians were less likely (53%) to prescribe arthritis meds when there were two medication options than when there was only one (72%)

Simonson & Tversky (1992) – more likely to buy $240 camera when more expensive option added ($170, $240, $470 instead of just $170 and $240)

Past History: Shen et al. (2010) – physician cesarean section decision affected by seriousness of preceding cases

Question 47

Context

Answer 47

Number of options
Had to decide which medication to give so did not give any
50% of people bought more expensive camera at 2 options
People chose $240 with 3 options
More likely to buy expensive option when more expensive options are present

Probability that physician ordered a c-section if beforehand cases were easy, opposite caused c section went down
1600 more people died after 9/11 from driving more often

Question 48

Rationalization (Tversky & Shafir, 1992)

Answer 48

You can buy a highly desired vacation package after passing an exam. Do you do it?
*Most of us (~60%) will because we’re celebrating
*But most of us (~60%) will also buy it after failing
—consolation
*However,if we don’t know how we did on the exam, only about 33% of us will buy it
*Pass/fail information isn’t relevant,but having some information so that we can justify it is obviously important

Passing or failing exam would result in 60% of taking vacation for different reasons though (pass/fail)
Only 33% if exam results were unknown
People were able to justify themselves when more info was given

Question 49

Sanfey et al. (2003)

Answer 49

UltimatumGame
* Proposer decides how to split money and responder decides whether to accept
*From a utility stand point should always accept
*Responder often rejects low offers because they became angry that offers were unfair
*Does not happen when dealing with a computer

Question 50

Sandy

Answer 50

Game where situation is essentially one person is given 10$ and decide how they want to split it up between others
Participants were the receiver so they were asked to chose money or reject
As long as the person is offering something, you should take it
Found when they thought they were playing with another person, wouldn’t accept the deal unless it was 3 dollars or more
35% or less accepted 1 dollar offer when they were dealing with another person
If it was computer, then it was nearly 70%
They thought it was unfair
Willing to sacrifice own benefit to punish others, but computer cannot be punished so there is no effect
fMRI was used
Prefrontal cortex was also involved with decision making process
Activation in right anterior insula correlated with likelihood of rejecting offer

Need to justify is just as important as utility
If we are put in situation, we would consider the best solution
People wouldn’t accept a bribe as it goes against their morals/nature
When others ask for your decisions, you should be able to justify them

Question 51

How Do We Decide?

Answer 51

utility is not the only goal, or even necessarily the most important one
Social and emotional factors are also important considerations
need for reasonable choices, with integrity
justification is critical—need to make sensible and defensible decisions
no accepted normative theory

Question 52

Two System (Processes)?

Answer 52

System 1:
– Intuitive
– Fast
– Unconscious
– Automatic

System 2:
– Reflective
– Slow
– Conscious
– Controlled