1. The Need for Psychological Science AP Psychology Ms. Desgrosellier 9.22.2009

2. Objectives SWBAT describe hindsight bias, and explain how it can make research findings seem like mere common sense. SWBAT describe hindsight bias, and explain how it can make research findings seem like mere common sense. SWBAT describe how overconfidence contaminates our everyday judgments SWBAT describe how overconfidence contaminates our everyday judgments

3. Why research in Psychology? Is psychology just documenting what we already know? Is psychology just documenting what we already know? People put a lot of faith in their intuition People put a lot of faith in their intuition Intuition and common sense have their limits Intuition and common sense have their limits e.g. Imagine folding a sheet of paper on itself 100 times. Roughly how thick would it be? e.g. Imagine folding a sheet of paper on itself 100 times. Roughly how thick would it be? A: If the paper is.1 mm thick, after 100 folds, it would be 800 trillion times the distance between the Earth and the Sun. A: If the paper is.1 mm thick, after 100 folds, it would be 800 trillion times the distance between the Earth and the Sun.

4. Hindsight Bias The tendency to believe, after learning an outcome, the one would have foreseen it (aka the I-knew-it-all-along phenomenon) The tendency to believe, after learning an outcome, the one would have foreseen it (aka the I-knew-it-all-along phenomenon) e.g. Pretend you’re trying to decide who to invite to homecoming. e.g. Pretend you’re trying to decide who to invite to homecoming. We have a harder time remembering when we’re wrong than when we’re right. We have a harder time remembering when we’re wrong than when we’re right.

5. Why do we need psychological research? We commonly make errors in our recollections and explanations We commonly make errors in our recollections and explanations Common sense is usually after the fact (made in hindsight) Common sense is usually after the fact (made in hindsight) Over 100 studies have observed hindsight bias in various countries and among both children and adults Over 100 studies have observed hindsight bias in various countries and among both children and adults

6. Psychology’s findings Some are intuitive Some are intuitive Others are not Others are not Research both inspires and overturns popular ideas Research both inspires and overturns popular ideas

7. True or false? Patients whose brains are surgically split down the middle survive and function much as they did before the surgery Patients whose brains are surgically split down the middle survive and function much as they did before the surgery Most infants recognize their own reflection in a mirror by the end of their first year Most infants recognize their own reflection in a mirror by the end of their first year Most abused children do not become abusive adults Most abused children do not become abusive adults Fears of harmless objects, such as flowers, are just as easy to acquire fears of potentially dangerous objects, such as snakes Fears of harmless objects, such as flowers, are just as easy to acquire fears of potentially dangerous objects, such as snakes

8. Overconfidence We tend to think we know more than we do. We tend to think we know more than we do. We also tend to be more confident than correct We also tend to be more confident than correct

9. Test yourself! How long do you think it would take you to solve the following anagrams? How long do you think it would take you to solve the following anagrams? –WREAT --> WATER –ETRYN --> ENTRY –GRABE --> BARGE Most people said around 10 seconds Most people said around 10 seconds Now, try to solve: RABDO Now, try to solve: RABDO In reality, closer to 3 minutes In reality, closer to 3 minutes

10. Robert Vallone, et al. (1990) Had college students predict at the beginning of the year whether they would drop a course, vote in an upcoming election, call their parents more than twice a month, etc. Had college students predict at the beginning of the year whether they would drop a course, vote in an upcoming election, call their parents more than twice a month, etc. On average, students felt 84% confident in making these self-predictions On average, students felt 84% confident in making these self-predictions –e.g. I am 84% sure I will vote in the upcoming election Later data collected showed that their predictions were only correct 71% of the time Later data collected showed that their predictions were only correct 71% of the time Even when they were 100% confident, they were only correct 85% of the time Even when they were 100% confident, they were only correct 85% of the time

11. Philip Tetlock (1998) Collected data from professionals (i.e. analysts, government experts, journalists) Collected data from professionals (i.e. analysts, government experts, journalists) On political, economic, and military situations e.g. Project how South Africa will be governed: On political, economic, and military situations e.g. Project how South Africa will be governed: –After 5 years, had them reflect on their predictions (South Africa is a multiracial democracy) –80% confidence were right less than 40% of the time –Even those who erred were likely to say that they were “basically” or “almost” right –Bottom line: overconfidence is hard to disprove or dislodge, no matter the actual outcome

12. Remember: Hindsight bias and overconfidence often lead us to overestimate our intuition. Hindsight bias and overconfidence often lead us to overestimate our intuition. Scientific inquiry can help us separate reality from illusions. Scientific inquiry can help us separate reality from illusions.