Judgement Bias 1

Question 1

Cognitive Heuristics

Answer 1

Reflexive mental shortcuts that simplify complex cognition and increase efficiency of thinking
Can lead to bias as not all info is considered

Question 2

Why do we use Heuristics?

Answer 2

Cognitive limitations e.g. attention
External constraints e.g. time
Motivational constraints

Question 3

Three Cognitive Heuristics

Answer 3

Availability: judging something based on ease of recall
Representativeness: judgments based on seemingly related things, violate normative principles when reasoning probability
Anchoring and Adjustments: Judgements based on numerical info

Question 4

Fire Article Study: Availability (Kahneman & Tversky, 1981)

Answer 4

P’s who read article about house fire overestimate their chance of involvement in a similar incident
The article serves as a ‘memory prime’ for event-consistent info

Question 5

Hit & Run study: Representativeness (Kahneman & Tversky, 1972)

Answer 5

P’s given scenario about hit and run accident involving a taxi
Told that blue cabs ran 15% of cabs in city, green ran 85% in city (vice versa in other condition)
Also told an eyewitness testimony of what colour it was
Result: P’s overestimated the probability of blue/green cab being involved: relied too much on eyewitness testimony rather than the proportions of taxis
Linked to conjuntion fallacy: non-logical thinking error occurring with probabilites

Question 6

Wheel of Fortune: Anchoring and Adjustment (Tversky & Kahneman, 1974)

Answer 6

Spin wheel of fortune numbers 1 (low anchor) to 64 (high anchor) then judge the percentage of African nations in the UN
Judgments were higher when the wheel stopped at high number, lower when wheel stopped at low number

Question 7

2 Major Biases in Judgment

Answer 7

• Overconfidence: typically evident in probabilistic reasoning
• Over optimism

Question 8

Explanations for Biases in Judgments

Answer 8

• Neglect of base-rate data

- Case-specific reasoning - making judgment based on single instance/example

Question 9

Planning Fallacy Bias

Answer 9

Underestimate task duration despite knowing previous task overran: over optimism
Due to: Neglecting base-rate data, focusing on aspects of current task

Question 10

Gambler’s Fallacy Bias (Gilovich et al, 2002)

Answer 10

Tendency to look for order/sequences
Misconception of ‘chance’
Don’t consider probability of stimulus occurring: violates ‘law of averages’