Lecture 9 - Hueristics Flashcards
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Describe an intuitive system (system 1) compared to a rational system (system 2).
Describe the ‘features’ of each.
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See slide 3-5
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Define ‘heuristics’
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“mental shortcuts” - intuitive mental operations that allow us to make a variety of judgements quickly and effectively.
See slide 6
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Define the availability heuristic.
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The process whereby judgements of frequency or probability rely on how readily pertinent instances come to mind
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Describe a classic experiment that demonstrates the availability hueristic.
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A classic experiment that demonstrates the availability heuristic, Tversky and Kahneman (1973):
PROCEDURE:
- Asked participants to judge letter frequencies:
“You will be given several letters of the alphabet, and you will be asked to judge whether these letters appear more often in the first or in the third position, and to estimate the ratio of the frequency with which they appear in these positions” (Tversky & Kahneman, 1973, p. 211).
- They presented the letters K, L, N, R, and V, all of them occurring more frequently in the third than in the first letter position in English words.
DV:
Decision whether a certain letter is more likely to appear in the first or in the third position.
RESULTS:
105 from 152 participants judged the first position to be more likely for the majority of letters.
EXPLANATION:
It is easier to retrieve letters in the first position than letters in the third position.
See slide 8-9
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Describe 2 studies that demonstrate the application of the availability heuristic.
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See slide 10-13
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Read slides 15-17
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Read slides 18-22
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Define the representativeness heuristic.
Describe a study that demonstrates this.
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The process whereby judgements of likelihood are based on assessments of similarity between individuals and group prototypes or between cause and effect.
Tversky & Kahneman (1974):
PROCEDURE:
- Gave Pps this passage:
“Steve is very shy and withdrawn, invariably helpful, but with little interest in people, or in the world of reality. A meek and tidy soul, he has need for order and structure, and a passion for detail” (Tversky & Kahneman, 1974, p. 1124)
- They were then asked:
Is he a farmer, a trapeze artist, a librarian, a salvage diver, or a surgeon?
People tend to substitute this question in their head to:
“Is it likely that A is part of category B? substituted by: Is A similar to prototypes of B? Does he sound like a B?”
ISSUES WITH THIS:
- Prior probabilities of outcomes – base rates.
> If he lives in a town with lots of farmers and only 2 librarians (base rate (how often something occurs in a population)) then statistically it’s more likely that he is a farmer…it is not just similarity that matters. So if you dont have a lot of information, you are more likely to think of base rates than similarities with the prototype.
- Quality of the information – what if I told you that this description of Steve was written 10 years ago?
- Completeness of information – what if we added a piece of information?
(lecture):
What are the issues with the representativeness heuristic?
(lecture) :
- Prior probabilities of outcomes – base rates.
- If he lives in a town with lots of farmers and only 2 librarians (base rate) then statistically it’s more likely that he is a farmer…it is not just similarity that matters.
- Quality of the information – what if I told you that this description of Steve was written 10 years ago?
- Completeness of information – what if we added a piece of information?
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Describe the planning fallacy.
Describe a study that demonstrates it.
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- Consistently overestimating how quickly and easily one can achieve a goal
- The tendency for people to be unrealistically optimistic about how quickly they can complete a project
- Only focusing on factors you can control, neglecting base rate info from other similar projects
Buehler et al. (1994):
PROCEDURE:
- They asked students towards the end of their year-long thesis project when they expected to submit their thesis.
RESULTS:
- Although the predicted completion time correlated highly with actual completion time (r = .77), students showed an optimistic bias: Only 30% of the students finished their project by the time they predicted.
- On average, students took 55 days to complete their theses. (22 days longer than they had anticipated and 7 days longer than the average prediction of the worst case.)
- People are highly confident about their predictions.
Why do people commit the planning fallacy?
- They focus on the different steps they will take in the future to complete the task, but neglect their earlier experience (prior probability) with finishing, or not finishing, projects that early.
TO TEST THIS:
- Participants say aloud every thought or idea that came to mind during predicting when they would finish their upcoming project.
RESULTS:
- An overwhelming majority (M = 74%) of the students’ thoughts were directed toward the future. Only 3% of the respondents thought about possible problems, only 7% of the thoughts were about past experiences, and only 1% of the thoughts were about past experiences others had with similar projects.
- > neglect of prior probabilities (representativeness heuristic)
THEN BUEHLER ASKED:
Is there a way to eliminate the planning fallacy?
HIS ANSWER: Linking relevant past experience to specific plans for their upcoming task (Buehler et al, 1994, Experiment 4).
TO TEST THIS:
- Pps were asked to predict when they would finish a computer assignment: 3 groups:
- Control: just a prediction
- Recall: recall past experiences before the prediction
- Recall Relevant: recalling past experiences and answer two questions: (a) when they would finish the project if they do as far before the deadline as in past projects; (b) to write down a typical scenario based on past experience.
RESULTS:
- The results showed that the planning fallacy was eliminated in the recall relevant group, but not in the two other groups.
(see slide 33, lecture 9, for table of results)
See slides 26-33
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Describe the anchoring and adjustment heuristic.
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See slides 34-36
(reading) :
- Gilovich et al. textbook on heuristics, pages 125-134
- Chapter 7 in Fiske, S.T., & Taylor, S.E. (2008 or 2013). Social Cognition. From Brains to Culture. New York: McGraw-Hill. p. 164-174 discusses heuristics including anchoring and adjustment; page numbers will differ for newer versions of this book (look for information on heuristics). This book chapter overlaps with the framing lecture.
- Epley, N., Keysar, B., Van Boven, L., & Gilovich, T. (2004). Perspective taking as egocentric anchoring and adjustment. Journal of Personality and Social Psychology, 87(3), 327-339. Research examining anchoring and adjustment in social perception.
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