Psych 253 - Lecture 3: Social Cognition and Heuristics pt. 1

schema

A schema is a mental model or representation that organizes the important information about a thing, person, or event

heuristic

A heuristic is a mental shortcut or rule of thumb that reduces complex mental problems to more simple rule-based decisions.

Heuristics are necessary because humans have bounded rationality: people try to make rational choices but are bounded by their cognitive limitations (e.g., lack of information, limited working memory, etc.)

1. Representativeness Heuristic

2. Availability Heuristic

3. Anchoring and Adjustment

Representativeness Heuristic

With the Representativeness Heuristic, the likelihood of an object or person belonging to a category is evaluated based on the extent to which the object or person appears similar to one’s mental representation of the category.

• The representative heuristic can lead to bad judgments when

• The schema is not specific enough, or wrong

• Base rates are not taken into consideration

• Sometimes, just wrong on a case-by-case basis

Availability Heuristic

A heuristic in which the frequency or likelihood of an event is

evaluated based on how easily instances of it come to mind.

Can be accurate: for example, if you remember your friend ordering red wine and pasta at previous dinners, this might help you accurately guess how likely this is

Anchoring and Adjustment

Anchoring and adjustment describes how people can be influenced by the highness or lowness of arbitrary numbers when they make subsequent numerical decisions

Example:

Kahneman and Tversky (1974)

Participants spun a wheel rigged to land on either “10” or “65” (IV)

Asked to “estimate the percentage of African countries in the UN” (DV)

10: Estimated ~25% of countries

65: Estimated ~45% of countries

People wrote down the last two digits of their social security number

Those with higher digits gave greater cost estimates for wine, trackballs, and textbooks

Leroy and the lottery tickets (Watch the video)

Leroy and the lottery tickets

• Setup: Do you buy a lottery ticket for $1 with 1/10 odds of winning $20?

• IV: 9 people with 1 lottery ticket each vs. 1 person with 9 lottery tickets

• DV: % of people who choose to buy the lottery ticket

The letter “R” and disasters

• Why is it that people guess that there are more English words that start

with “R” than have “R” as the third letter?

• Know that people overestimate deaths for things like fireworks and

plane crashes, but underestimate them for things like drowning and

asthma

• Shifting comparisons (an extension of anchoring and adjustment)

• People say they would drive across town to save 50% on a speaker but

not .003% on a car, even when the absolute value is the same (e.g.,

$100), because the relative value changes

• People are more likely to buy the $33 bottle of wine instead of a $29 bottle of when you place a $100 bottle of wine next to them, because

the relative cost changes (even though the absolute cost stays the

same)

• Do not worry about the rest of the studies or the specific

concepts about the “past versus the possible” or “time and

value”; they are interesting but will not be tested