(Cognitive) Decision making and reasoning Flashcards
week 10
Heuristics are
efficient cognitive processes, conscious or unconscious that ignore part of the information. (Gigerenzer & Gaissmaier, 2011)
Comes from the Greek; ‘serving to find out and discover’. Essentiall, rules of thumb.
All heuristics rely on:
a. examining fewer cues
b. reducing the effor of retrieving cues
c. simplifying the weighting of cues
d. integrating less information or examining few alternatives
Shah & Oppenheimer, 2008
Using heuristics saves effort, meaning decisions may have greater errors than ‘rational’ decisions defined by logic or statistics.
Availability Heuristic
People estimate the liklihood or frequency by the ease with which examples can be brought to mind.
Examples include, couples who self assess their contributions to the housework, both have more ease remembering instances of their own effort and therefore they’re estimations often total to more than 100%.
Availibility will often be a valid cue for estimates of liklihood.
However, recent events and emotionally salient events are easier to recollect.
For example, perceived risk of air travel rises in the immediate wake of an air disaster.
Study of Availability
Schwarz (1990s)
Investigaed whether heuristic works due to number of instances retrienved or ease with which they come to mind.
Their task: List 6 instances in which you have behaved assertively. How assertive are you on a scale of 1-5 (1= not assertive at all, 5= extremely assertive)?
And task was replicated with 12 instances. PPs who had listed 12 instances rated themselves as less assertive than those who had listed 6. Fluent retrieval trumped number retrieved.
Representativeness Heuristic
Used to determine how likely it is that an event is a member of a category by considering how similar or typical the event is of the category. Uses memories of a prototype, stereotype, or average. This heuristic tends to ignore the base rate (the true liklihood that someone belongs to the category you’re matching them to based on stereotype)
An example of the representativeness heuristic
Judging the liklihood that someone is a librarian by the extent to which that person resembles a ‘typical’ librarian (glasses, holding a book, tartan skirt). However it neglects consideration of the relative prevalence of librarians in society as a whole: the base rate.
Kahneman& Tversky (1973): Prior probabilities are largely ignored when individuating information is available (even if it is worthless)
Study of representativeness
Kahneman & Tversky (1973)
K & T narrated a scenario about ‘Jack’ and qualities about him, his family, hobbies, etc. Then asked pps ‘is Jack and engineer?’
Half the pps had been told the description was taken from a sample of 70 engineers and 30 lawyers. The other half of the pps were told the opposite. However the mean estimates of if Jack was an engineer in the two groups was only slightly different (55 vs 50%).
This shows that people ignore base rate information and make judgements using the individuating information.
Anchor & Adjust Heuristic
Used when people make estimates by starting from an initial value and then adjust it to arrive at their final estimate.
An example of the Anchor and Adjust heuristic
When you’re buying a coffee and you’re offered a medium or large, even though small is an option. This is a technique may use in the service industry as the framing of the question influences response, and this can increase sales.
Study on Anchor and Adjust
Northcraft & Neale (1987)
48 students and 21 real estate agents all inspected a specific house and given a 10pg info pack about the house. Then exposed on of two listing prices and asked to provide their own estimates of market value, listing price, what they would actually pay, and a minimum selling price.
They found that the given asking price swayed valuations by 11-14% even when the given price was less credible.
What is reasoning?
Reasoning is a form of thinking strongly influenced by what we know about formal logic.
‘If john finds out he will be furious’. Later you are told ‘John found out’. If you conclude that ‘John was furious’ then you have engaged in reasoning. You have inferred a conclusion from some premises.
Most reasoning takes the form of…
‘if , then .’
This is a conditional statement. If p, then q. p is the antecedent, q is the consequent.
Modus Ponens (MP)
If it is raining (p) then Micheal is wet (q).
Assuming that if p then q is true, and p alone is true, then q must also be true. no other possibility.
First line of the table
Modus Tollens (MT)
If the rule is true (if p then q) and q is false (not q) then p must also be false (not p). So if the conditional is true and Micheal is not wet, then it cannot be raining.
