Thinking Like a Scientist Module 4: The Need for Psychological Science

1. Thinking Like a ScientistModule 4: The Need for Psychological Science

2. Limits of Intuition • Do the following simple addition problem in your head: • Start with 1000 and add 40 to it. • Add 1000 • Add another 30 followed by another 1000. • Next add 20. • Add another 1000. • Add 10 • What is the number? • 5000? • WRONG! It’s 4100

3. Let’s do the Math… • 1000 + 40 = 1040 • 1040 + 1000 = 2040 • 2040 + 30 = 2070 • 2070 + 1000 = 3070 • 3070 + 20 = 3090 • 3090 + 1000 = 4090 • 4090 + 10 = 4100 • Your mind sometimes jumps to the wrong conclusion!

4. How scientific are you? • If you drop a bullet off a table 3 feet high, and fire another one straight across an empty football field, which hits the ground first? • Bullets hit at the same time because downward velocity is independent of horizontal velocity. • A ball rolls down a spiral track. The end of the track curves left. What path does the ball take when it leaves the track? • It goes in a straight line. Only objects acted on by a constant lateral force curve.

5. Common Sense • Conclusions based solely on personal experience and sensible logic • Typically describes what has happened rather than what will happen • Can lead to incorrect conclusions because: • People interpret what common sense means differently • You may be missing important information that would help you come to a reasonable conclusion

6. Did you know… • It is nearly impossible to fold a regular sheet of paper in half more than 7 times. • Go ahead and try! • Mythbusters pulled it off with a piece of paper as big as an airplane hanger and a steam roller. (4 min)

8. BOREDOM BUSTER! Common Sense tells us squirrels are harmless… OR ARE THEY? RUNNING OF THE SQUIRRELS

9. Science vs. Common Sense • Science helps build explanations that are consistent and predictive rather than conflicting and describing the past (hindsight) • Science is based on • knowledge of facts • developing theories • testing hypotheses • public and repeatable procedures • Common Sense is based on prior experience

10. The “I knew it all along” phenomenon. • The Tendency to exaggerate one’s ability to have foreseen how something would turn out after learning the outcome. Hindsight Bias • You forget that previously you unsure how things would turn out and think instead you always knew what the outcome would be. • 3 Level Process: • Memory distortion, involves misremembering an earlier opinion or judgment (“I said it would happen”). • Inevitability, centers on our belief that the event was inevitable (“It had to happen”). • Predictability/Foreseeability, involves the belief that we personally could have foreseen the event (“I knew it would happen”). EXAMPLE: You get an acceptance letter from college and say, “I knew I’d get in.” but in reality a week ago you were telling your friends how nervous you were that you hadn’t heard from the college yet. See Captain Hindsight from South Park clip (start at :40)

11. More Hindsight Bias Examples • When a movie reaches its end & you discover who the killer really was, you might look back on your memory of the film and misrember your initial impressions of the guilty character. • Looking back at situations in the film we begin to believe that it was clear what was going to happen. • You walk away from the film thinking that you knew it all along but in reality, you probably didn’t

12. Overconfidence • Tendency to overestimate the accuracy of our current knowledge • We are more confident than we are correct. • How long will it take you to do your homework? – Do you tend to underestimate how long it takes? - Overconfidence is why! • “Man will never reach the moon, regardless of all future scientific advances.” - Lee DeForest, inventor of vacuum tube, 1957 • “Nuclear powered vacuum cleaners will probably be a reality within 10 years.” - Alex Lewyt, manufacturer of vacuum cleaners, 1955

13. What are the Odds of Each?

14. What are the Odds of Each? 1 in 2,598,960

15. What are the Odds of Each? 1 in 2,598,960 1 in 2,598,960

16. Perceiving Order in Random Events • We are naturally programmed to look for patterns. • Random sequences often don’t look random • Prior events don’t determine future outcomes • With a large enough sample, the impossible become inevitable. • Given the billions of events that occur each day and given enough days, some stunning coincidences are sure to occur Virginia couple wins lottery 3 times in one month!

18. 5 Common Types of CoincidenceCompiled by The Winton Programme for the Public Understanding of Risk • Surprising Repetitions • Multiple members of the same family who are born with the same birthday • Simultaneous Events • 2 people who phone each other at the exactly the same time • Parallel Lives • 2 people in a small group who share a birthday or an unusual name • Uncanny Patterns • Picking letters in Scrabble that spell your name • Unlikely Chains of Events • Losing false teeth overboard and finding them inside a fish you caught 20 years later

19. Confirmation Bias • Our tendency to search for information that confirms our beliefs & ignore evidence that disputes our beliefs. • Try this card trick: http://www.caveofmagic.com/ • This works because we only look for our chosen card confirming Simeon’s mental telepathy and ignore the fact that second set of cards is in fact, an entirely new set! • NONE of the cards in the new set is the same as the old one so of course the card you picked is missing.

22. The Rat is Always Right • Scientists need to be: • Curious – striving to explore and understand • Skeptical – Always ask… • What do you mean? • How do you know? • Humble – be willing to admit when the evidence shows we’re wrong.

23. How Do They Know That?!Thinking Critically • Don’t blindly accept arguments and conclusions • Look for evidence gathered scientifically • Who is providing the evidence? Are they biased? • Are the right conclusions being drawn?

24. DAILY DOUBLE

25. QUESTIONWhat is the difference between Common Sense and Science? ANSWER: Common sense relies on the past and may be wrong. Science uses facts to provide consistent predictions