Judgement

Question 1

Heuristics and biases approach (Tversky & Kahneman, 1983)

Answer 1

• Showed that when participants are asked to rate the likelihood of several alternatives, including single and joint events, they often make a ‘conjunction fallacy’
• Conjunction Fallacy- is an error in decision making where people judge that a conjunction of two possible events is more likely than one of the constituent events

(Tversky & Kahneman, 1983), “people rely on the limited number of heuristics which sometimes yield reasonable judgements and sometimes lead to severe and systematic errors”

Question 2

The conjunction fallacy

Answer 2

• 85% of undergraduates judged h (bank teller and feminist) to be more likely than f (bank teller)

But h is of the form ‘Linda is both X and Y’
F is of the form ‘Linda is X’

So, h cannot be more likely than f

(Tversky & Kahneman, 1983) gave 142 people a simplified version of the people containing only the two options (f and h)
- Still, 85% made the conjunction fallacy

Question 3

Representativeness heuristic

Answer 3

It is a mental shortcut that we often use when estimating probabilities
- When we are trying to assess how likely a certain event is, we often make our decision by assessing how similar it is to an existing mental stereotype
- Biased judgements made in everyday life
An example of this a representativeness heuristic is thinking that because someone is wearing a suit and tie and carrying a briefcase, they must be a lawyer because they look like the stereotype of a lawyer.

Question 4

What is Availability heuristic?

Answer 4

– the easier it is to bring an event to mind, the more likely that event is judged to be

Question 5

Availability heuristic
(Coombs & Slovic, 1979)

Answer 5

• Newspaper reports over-represented more ‘dramatic’ causes of death (natural disasters, accidents, homicide etc)
• People’s risk judgements were related to frequency of media coverage
• More evidence for use of an availability heuristic

Question 6

End anchoring
(Tversky & Kahneman, 1974)

Answer 6

The anchoring effect is a cognitive bias that described the common human tendency to rely too heavily on the first piece of information offered (‘the anchor’) when making decisions

During decision-making, anchoring occurs when individuals use an initial piece of information to make subsequent judgments

Question 7

Frequentist approach

Answer 7

Is an approach that draws conclusions from statistical samples – based on the number of times an event is expected to occur

• claims that people have evolved to think in terms of frequencies (out of 10 times, this event happens once) rather than single event probabilities (10% chance of this happening)

For example,
Saying that the probability of a coin landing heads being 0.5% means that if you were to flip the coin enough times, we would see heads 50% of the time.

(Fieldler, 1988) used probability and frequency representations of seven problems, including the Linda problem.

(Fieldler, 1988) Experiment 1 - reported 73% conjunction violations in the probability representation and 23% in the frequency representation, averaged across all seven problems.