Class Notes (806,513)
Canada (492,267)
Psychology (3,805)
PSYC 2650 (166)

Chapter 12 notes.docx

5 Pages
Unlock Document

University of Guelph
PSYC 2650
Anneke Olthof

Cognitive Psychology: Chapter 12 Judgment Heuristics - Induction is a pattern of reasoning in which one seeks to draw general claims from specific bits of evidence  Based on what you know about Allen, what is likely to cheer him up today?  Based on what you know about cars, what is the best kind to buy? - When we discuss induction and other aspects of human reasoning, we will often be comparing: • A descriptive account, telling us how reasoning ordinarily proceeds (including the errors) • A normative account, telling us how we “ought to” reason - Note that induction – drawing a general conclusion based on previous observations and experiences – relies on memory - If memories are selective, incomplete, or distorted, then the validity of the induction will be questionable  “I can always tell when someone is lying.”  “Creative people are usually a little bit crazy.”  “This year’s freshmen seem more mature than last year.” - Recall that a heuristic is a strategy that is reasonably efficient and works most of the time. In using a heuristic, we gain efficiency at the expense of more error - Judgment heuristics include:  Attribute substitution  Availability heuristic  Representativeness heuristic - Attribute substitution is a strategy used when we do not have easy access to a desired piece of information - Instead, we base our decision on readily available information (a proxy or index) that we believe is correlated with the desired information - For example, people often use “ease of reading” as a substitution for “author intelligence,” assuming that, usually, smart authors can express concepts more clearly - The availability heuristic is a specific case of attribute substitution - When assessing the frequency or likelihood of an event, the ease with which examples come to mind is used as an index of frequency or likelihood - For instance, consider: • In the English language, are there more words that start with the letter “R” or with the letter “R” in the third position? • Who washes the dishes more often, you or your roommates? • Are more deaths caused by crimes or by diseases? - The availability heuristic may lead us to think that there are more words that begin with “R” - In reality, there are more words with “R” in the third position, but words that begin with “R” are easier to bring to mind - The availability heuristic may lead us to believe that we always do the housework ourselves - The availability heuristic may lead us to think that more deaths are caused by crimes or accidents than by disease - In reality, far more deaths are caused by disease - As another example of the availability heuristic, consider a study in which participants recalled past episodes in which they had been assertive (Schwarz et al., 1991) - Some people were asked to give 6 examples and others 12 examples - Which group then judged themselves to be more assertive in general? - The group that was asked to give 6 examples of having been assertive judged themselves as more assertive in general - The availability heuristic may explain this result: 6 examples come to mind more easily than 12, which would signal to the 6-example group that being assertive is a frequent occurrence - The representativeness heuristic is another example of attribute substitution - People often assume when making a judgment about a member of a category, that the instances of the category resemble the prototype for the category and that the prototype resembles each instance - For instance, consider: • Do you assume anything about someone if you discover that he or she is a lawyer or an engineer? • If a coin toss results in “heads” six times in a row, what are the odds of getting “tails” the seventh time? • If you hear an anecdote about a marathon runner who has smoked for decades and is perfectly healthy, does this mean that smoking is safe? - The representativeness heuristic may lead us to believe that all lawyers or all engineers are homogeneous (a stereotype) - We assume that each individual member of a category has the traits we associate with the category overall - The representativeness heuristic may lead us to believe that the seventh coin toss is more likely to be tails (the gambler’s fallacy), but the odds are still 50-50 - We assume that what is true of a category as a whole is true of specific instances we encounter of that category - This is an example of reasoning from the population to an instance - The representativeness heuristic may lead us to believe that smoking must be okay for your health based on one example (anecdotal evidence or “man who” stories) - We assume that what is true of one instance of the category must be true of the category as a whole - This is an example of reasoning from one instance to the population - As another example of the representativeness heuristic, consider a study in which participants watched videos of a “prison guard” discussing his job (Hamill et al., 1980) - One variable of the study was whether the guard was compassionate or contemptuous. Another variable was whether the participants were told the guard was representative of all guards - What did participants later conclude about prison guards in general? - Participants were only affected by which video they had seen, not the instructions given - Those who had seen the compassionate guard had positive views of guards in general, and those who had seen the contemptuous guard had negative views of guards in general Anchoring - Anchoring is the tendency to use the first-available estimate as a reference point or anchor for the final estimate - As the result, the first-available estimate has a great influence on the final estimate - For instance, estimates of how long Mahatma Gandhi lived will be influenced by whether the experimenter first asks if he lived past 9 years, compared to 1
More Less

Related notes for PSYC 2650

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.