Thinking Like a Scientist Psychology as a Science

1. Thinking Like a ScientistPsychology as a 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)

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

9. Hindsight Bias • 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. • 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”). • 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)

10. 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

11. What are the Odds of Each?

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

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

14. 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 • “Reagan doesn’t have the presidential look.” - United Artist Executive in turning Reagan down for the starring role in The Best Man, 1964.

15. 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!

17. 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

18. 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.

21. 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.

22. 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?

23. DAILY DOUBLE

24. 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