Week 7 Lecture 6 - reasoning and decision making

Question 1

What are heuristics?

Answer 1

Simplifying strategies that reduce effort but are prone to bias/error

Question 2

What is ecological rationality?

Answer 2

Apparent biases may be rational responses given then ecology of the human decision making

Question 3

What are 2 explanation for why humans are bad at making probability judgements?

Answer 3

• heuristics
• ecological rationality

Question 4

What are the 2 systems involved in your decision making?

Answer 4

• fast intuitive one (used most)
• slow rational one

Question 5

What are 3 examples of heuristics?

Answer 5

• availability
• representativeness
• anchoring

Question 6

What is the availability heuristic?

Answer 6

If you can bring to mind something e.g., an event, it is likely that it occur frequently, if you cannot it is likely not a common occurrence

Question 7

How can availability heuristics bring in error?

Answer 7

may be more likely to remember shocking or frightening events leading you to think they occur often e.g., shark attacks

Question 8

What did a study find when asking people to estimate causes of death? Which heuristic is this consistent with?

Answer 8

people:
- overestimate rare events
- underestimate common events

consistent with availability heuristics

Question 9

What did a study investigating the effect of memory on availability find?

Answer 9

• it is easier to remember famous names than less famous names
• ppts judged that the gender with famous names was more frequent (as it is easier to bring the famous names to mind)

Question 10

What can the availability heuristic lead to?

Answer 10

The conjunction fallacy

Question 11

What is the conjunction fallacy?

Answer 11

A common reasoning error in which we believe that when two events are happening in conjunction one is more probable than the other
This is because people will find one easier to bring to mind than the other so think it occur more often

Question 12

Given an example of a conjunction fallacy

Answer 12

“In 4 pages of a novel, how many words would you expect to find that have the form “___ing” and “_____n_”

Question 13

What is the representativeness heuristic?

Answer 13

judgements of probability are based on assessments of similarity

Question 14

What is base rate neglect an example of?

Answer 14

the representativeness heuristic

Question 15

What is base rate neglect?

Answer 15

the tendency to underweight base rate or prior information compared with current, individuating information when estimating probability of uncertain events

Question 16

What is the anchoring heuristic?

Answer 16

the assimilation of a numeric estimate towards another, anchor value

Question 17

What is “anchor-and-adjust”?

Answer 17

we use the anchor as an initial estimate of the target value and adjust from that starting point in the right direction; because the adjustment is effortful, we often adjust insufficiently and so our judgment is biased towards the anchor value

Question 18

What is a potential issue with the anchoring heuisitc?

Answer 18

Incentive, warnings and cognitive capacity have little effect on accuracy
Many other mechanism produce the same effect

Question 19

What are 2 formats of ecological rationality?

Answer 19

• natural frequencies
• misperception of randomness

Question 20

What is the inverse fallacy?

Answer 20

the mistaken belief that the probability of the data given the null hypothesis, P(D|H0), is equivalent to the probability of the null hypothesis given the data, P(H0|D).

Question 21

What does Bayes theorem tell us about probabilties?

Answer 21

Bayes’ theorem tells us how we should update our beliefs to give the posterior probability that H is true, given our prior belief and the new data

Question 22

What are natural frequencies?

Answer 22

A joint frequency of two events, such as the number of patients with disease and who have a positive test result, and is an alternative to presenting the same information in conditional probabilities

presenting information with rational numbers rather than percentages is easier to understand

Question 23

Are people good at judging when something is random or not?

Answer 23

no

Question 24

What is the Gambler’s Fallacy consistent with?

Answer 24

Misconceptions of randomness

Question 25

What is the Gambler’s Fallacy?

Answer 25

The belief that a run of one outcome increases the probability of another (when the events are actually independent)

Question 26

Give an example of the Gambler’s Fallacy

Answer 26

the probability of getting “heads” from a fair coin is the same after a run of 3 heads as after a run of 3 tails

Question 27

What is the Hot Hand Fallacy consistent with?

Answer 27

Misconceptions of randomness

Question 28

What is the Hot Hand Fallacy?

Answer 28

the expectation of “streaks” in sequences of hits and misses whose probabilities are, in fact, independent

Question 29

Give an example of the Hot Hand Fallacy?

Answer 29

basketball fans belie that a player’s next shot was more likely to score after a run of successful shots than after a run of misses

Question 30

Which heuristic can be used to explain both the Gambler’s Fallacy and the Hot Hand Fallacy?

Answer 30

The Representativeness heuristic

Problematic as the same heuristic is being used to explain opposite effects

Question 31

What is an alternative explanation for the Gambler’s Fallacy?

Answer 31

Past experience:
- Inappropriate generalization of past
experience
- Random mechanical outcomes = Sampling without replacement
- Intentional human performance = Positive
recency

e.g., taking a red sweet from a bowl means its less likely to take another red sweet next time

Question 32

What is an alternative explanation for the Hot Hand Fallacy?

Answer 32

Past experience:
- many aspects of intentional human performance really do show positive recency.
- e.g., If you practice a new game, your shooting success will increase.
- HHF = an appropriate generalization of past experience to situations which also use human performance, but where the outcome probabilities are in fact independent.

Question 33

How could memory constraints explain misconceptions of randomness?

Answer 33

that the supposed “fallacies” of human judgment and decision-making are often perfectly rational given the finite and imperfect information afforded by the environment and our limited mental capacities.

Question 34

What are 2 realistic conditions to consider about the human condition when looking at the properties of fair coin toss

Answer 34

• People only ever see finite sequences
• People can only hold a short subsection of
  a sequence in memory (e.g., the last 4
  outcomes)