14. D. T. Levin and D. J. Simons, “Failure to Detect Changes to Attended Objects in Motion Pictures,” Psychonomic Bulletin and Review 4 (1997): 501–506. You can view the film at www.theinvisiblegorilla.com.
15. Subjects answering yes were then asked to describe the changes they noticed. Only one subject reported noticing anything, and that person’s description was sufficiently vague that it was not clear whether the individual had actually noticed a change.
16. The term “change blindness” was coined in this article: R. A. Rensink, J. K. O’Regan, and J. J. Clark, “To See or Not to See: The Need for Attention to Perceive Changes in Scenes,” Psychological Science 8 (1997): 368–373.
17. The term “change blindness blindness” and the data described in this paragraph come from: D. T. Levin, N. Momen, S. B. Drivdahl, and D. J. Simons, “Change Blindness Blindness: The Metacognitive Error of Overestimating Change-Detection Ability,” Visual Cognition 7 (2000): 397–412. Of 300 subjects, 76 percent predicted they would notice the change to the plates, and 90 percent of 297 subjects predicted they would notice the change to the scarf.
18. These quoted responses are taken from an unpublished replication of the earlier studies (which were done at Cornell by the two Dans) that Dan conducted while he was at Harvard. They are typical of responses written by subjects in all of these change blindness experiments. Levin and Simons (“Failure to Detect Changes to Attended Objects”) found that across four different pairs of actors performing two different simple actions, approximately two-thirds of the subjects failed to report any change. For the particular video described in the text, none of the subjects in the original experiment reported the change.
19. See Levin and Simons, “Failure to Detect Changes to Attended Objects.” A video of a subject participating in this study can be viewed at www.theinvisiblegorilla.com.
20. Script supervisors have many responsibilities on set, including keeping track of all the details of each take (e.g., the cameras used, what actors said, how the action progressed, how long the shot was, etc.). Their extensive notes guide the entire postproduction process.
21. Quotes from Trudy Ramirez are from an e-mail correspondence on June 2–6, 2009, and a telephone interview with Dan on June 6, 2009. Dan also corresponded with a second script supervisor, Melissa Sanchez (on November 14, 2004, and June 2–3, 2009), who was tremendously helpful in guiding our writing of this section.
22. Two of the best-known training manuals for script supervisors, Script Supervising and Film Continuity by Pat Miller and The Continuity Supervisor by Avril Rowlands, give advice that is entirely consistent with what Trudy Ramirez said: Don’t count on your ability to remember visual details. Miller, who advises readers to take photographs and copious notes, recognizes the limits of memory: “It is humanly impossible and patently unnecessary for you to simultaneously watch and note every detail in a scene. The mark of a competent continuity supervisor is not so much the possession of extraordinary powers of observation … but your confidence in knowing what is important to observe” (p. 177). Rowlands agrees: “… it is what you notice that is important. You will never notice everything that is happening within a shot and it is not necessary that you should, providing the things you do notice and write down are those which are important in order to preserve continuity” (p. 68).
23. Of 108 undergraduates, 98 percent predicted they would notice the person change (Levin et al., “Change Blindness Blindness”).
24. D. J. Simons and D. T. Levin, “Failure to Detect Changes to People During a Real-World Interaction,” Psychonomic Bulletin and Review 5 (1998): 644–649.
25. This experiment is described in D. T. Levin, D. J. Simons, B. L. Angelone, and C. F. Chabris, “Memory for Centrally Attended Changing Objects in an Incidental Real-World Change Detection Paradigm,” British Journal of Psychology 93 (2002): 289–302. A demonstration of the experiment was broadcast on the BBC program Brain Story and was also re-created on Dateline NBC in 2003.
26. For an overview of the evidence for change blindness, see D. J. Simons and M. Ambinder, “Change Blindness: Theory and Consequences,” Current Directions in Psychological Science, 14 (2005): 44–48.
27. Simons and Levin, “Failure to Detect Changes to People.” The studies in which we changed the race or sex of the actor have not yet been published. We conducted one study in which we replaced a male actor with a female actor in the counter paradigm mentioned earlier, and nobody missed the change. Dan and his former graduate student Stephen Mitroff also conducted a series of video-based change detection experiments in which the race or sex of an actor was changed. Again, nobody missed these changes.
28. Of people who noticed the change, 81 percent correctly selected the first actor from the lineup, and 73 percent correctly picked the second. Those missing the change selected the correct first actor 37 percent of the time and the correct second actor 32 percent of the time. See Levin et al., “Memory for Centrally Attended Changing Objects.”
29. Details of this case and quotes are taken from a story by M. Rich: “Christmas Essay Was Not His, Author Admits,” The New York Times, January 9, 2009.
30. K. A. Wade, M. Garry, J. D. Read, and S. Lindsay, “A Picture Is Worth a Thousand Lies: Using False Photographs to Create False Childhood Memories,” Psychonomic Bulletin and Review 9 (2002): 597–603.
31. D. L. M. Sacchi, F. Agnoli, and E. F. Loftus, “Changing History: Doctored Photographs Affect Memory for Past Public Events,” Applied Cognitive Psychology 21 (2007): 1005–1022. The story of this famous photograph, which was really four different photographs shot by four separate photographers, is discussed in the New York Times “Lens” blog (lens.blogs.nytimes.com/2009/06/03/behind-the-scenes-tank-man-of-tiananmen/).
32. S. J. Sharman, M. Garry, J. A. Jacobson, E. F. Loftus, and P. H. Ditto, “False Memories for End-of-Life Decisions,” Health Psychology 27 (2008): 291–296. The Seinfeld quote is from “The Comeback,” Episode 147, broadcast January 30, 1997. A transcript of the dialog can be found online at www.seinfeldscripts.com/TheComeback.html (accessed July 24, 2009).
33. K. Frankovic, “To Tell the Truth to Pollsters,” cbsnews.com, August 15, 2007 (www.cbsnews.com/stories/2007/08/15/opinion/pollpositions
/main3169223.shtml).
34. F. W. Colgrove, “Individual Memories,” American Journal of Psychology 10 (1899): 228–255. The quote is from pages 247–248.
35. R. Brown and J. Kulik, “Flashbulb Memories,” Cognition 5 (1977): 73–99.
36. Bush’s false memory was documented in D. L. Greenberg, “President Bush’s False ‘Flashbulb’ Memory of 9/11/01,” Applied Cognitive Psychology 18 (2004): 363–370. The video footage of the first plane hitting the World Trade Center came from a French film crew that had been following a New York City firefighter and his comrades for a documentary. They happened to be filming firefighters investigating a gas leak near the World Trade Center when they heard a loud noise overhead. They turned their camera up just in time to catch the first plane hitting the first building. CBS broadcast its documentary in March 2002, six months after the attack. Clips of the relevant portion can be found on YouTube. See also J. Kiesewetter, “Brothers Filming Documentary Caught ‘9/11’ on Tape,” Gannett News Service, March 10, 2002.
37. At the time of this writing, there are many websites that promote the idea that President Bush knew about the attacks in advance, citing his comments about seeing the first plane as evidence. A Google search with the terms “Bush,” “first,” “plane,” and “9/11” turns up many of them. Incidentally, if Bush had been so diabolically clever as to plan the 9/11 attacks, feign surprise, and cover everything up from Congress, the courts, and the media, why would he then reveal his involvement to a child? Conspiracy theories tend to fail spectacularly another test of cognitive plausibility by depending on the notion that a select few individuals have near-superhuman abilities to control and coordinate events and information.
38. U. Neisser and N. Harsch, “Phantom Flas
hbulbs: False Recollections of Hearing the News About Challenger,” in Affect and Accuracy in Recall: Studies of “Flashbulb” Memories, ed. E. Winograd and U. Neisser (Cambridge: Cambridge University Press, 1992).
39. “The Knight Tape,” CNN/Sports Illustrated, September 9, 2000.
40. From a conversation on November 27, 2008, and a letter from Daniel D. Chabris to Christopher F. Chabris (dated December 2, 2008).
41. Interviews and conversation with Leslie Meltzer and Tyce Palmaffy.
42. J. M. Talarico and D. C. Rubin, “Confidence, Not Consistency, Characterizes Flashbulb Memories,” Psychological Science 14 (2003): 455–461.
43. Details about the case of Hillary Clinton’s Bosnia memory are drawn from a fact-checking story published as “Hillary’s Balkan Adventure, Part II,” washingtonpost.com, March 21, 2008. The Peggy Noonan quote is from her column “Getting Mrs. Clinton,” The Wall Street Journal, March 28, 2008. The satirical cover image was published by The New Republic, May 7, 2008; the image can be seen at meaningfuldistractions.files.wordpress.com/2008/05/newrepubhill.jpg (accessed August 30, 2009). Bill Clinton’s comments came in a speech in a high school gymnasium in Indiana. He was quoted as saying, in reference to the people attacking his wife’s statements, “and some of them when they’re 60 they’ll forget something when they’re tired at 11 at night, too.” These comments were reported by Mike Memoli and posted to the MSNBC website by Domenico Montanaro in “Bill’s Back on the Trail,” MSNBC First Read, April 10, 2008. Hillary Clinton did later joke about the claims when appearing on the NBC Tonight Show with Jay Leno (April 3, 2008): “I was worried I wasn’t going to make it … I was pinned down by sniper fire at the Burbank airport.”
44. In this experiment, 41 percent of the 59 subjects thought they could recall ten or more digits. The maximum number of random digits a person can hear and recall successfully is known as their “digit span.” Given reasonable assumptions of a population mean digit span of 6.6 digits and standard deviation of 1.1 digits, only about 0.5 percent of people (1 in 200) should have a digit span of ten or greater. These results and analyses are presented in Experiment 2 of Levin et al., “Change Blindness Blindness.”
45. For a discussion of how intuitions about the accuracy of memory interact with the nature of the recollective experience, see W. F. Brewer and C. Sampaio, “Processes Leading to Confidence and Accuracy in Sentence Recognition: A Metamemory Approach,” Memory 14 (2006): 540–552.
46. T. Sharot, M. R. Delgado, and E. A. Phelps (2004), “How Emotion Enhances the Feeling of Remembering,” Nature Neuroscience 7 (2004): 1376–1380.
Chapter 3: What Smart Chess Players and Stupid Criminals Have in Common
1. For information about Lyme disease, see G. P. Wormser et al., “The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America,” IDSA Guidelines 43 (2006): 1089–1134.
2. We surveyed 103 players in all; 31 in Parsippany and 72 in Philadelphia.
3. Our follow-up examination of ratings from years after the original survey necessarily included only those players who kept playing tournament chess through that period. Others became inactive, perhaps because their ratings were not improving as they had hoped. When those players are added to the analysis, using the last ratings they had before they dropped out, the level of overconfidence is 71 points at five years (as opposed to 54 points without those players).
4. C. Darwin, The Descent of Man (London: John Murray, 1871), 3.
5. A transcript of the dialogue from Take the Money and Run (which was released in 1969) can be found online, www.script-o-rama.com/movie_scripts/t/take-the-money-and-run-script.html (accessed April 24, 2009).
6. D. Lehr, The Fence (New York: HarperCollins, 2009), 39–40.
7. Evidence that criminals tend to be less intelligent comes from pp. 247–249 of R. J. Herrnstein and C. Murray, The Bell Curve: Intelligence and Class Structure in American Life (New York: Free Press, 1994). Examples of inept criminals are drawn from “Daft Burglar Writes Name on Wall,” BBC News, September 6, 2007 (news.bbc.co.uk/2/hi/uk_news/england/manchester/6981558.stm); and “Man Jailed After Trying to Pass $1 Million Bill at Pittsburgh Giant Eagle,” WTAE-TV4, October 9, 2007 (www.thepittsburghchannel.com/news/14300133/detail.html?rss=pit&psp=news). The largest bill in circulation is the $100 bill. Apparently a set of fake $1 million notes was distributed by a church in Texas; Porter was not the only person who tried to pass one. It is not clear whether the people who tried to spend them actually thought they were legal tender.
8. The experiments described in this section are reported in J. Kruger and D. Dunning, “Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments,” Journal of Personality and Social Psychology 77 (1999): 1121–1134. The finding that the less competent are more prone to overestimate their ability than the highly competent has been called the “Dunning-Kruger Effect,” presumably because Dunning was a professor and Kruger was a graduate student at the time. It earned its discoverers the Ig Nobel Prize for psychology in 2000 (improbable.com/ig/igpastwinners.html). Kruger is now a professor at New York University’s business school.
9. Kruger and Dunning, “Unskilled and Unaware of It,” 1121. In Little Rock, Arkansas, in 2007 a man named Langston Robbins entered a bank, walked right past an off-duty cop working as a security guard, and placed a holdup note in front of the teller. The cop arrested him after a struggle and a short chase. Lieutentant Terry Hastings of the Little Rock police told the Associated Press, “I just don’t know why he didn’t see a uniformed police officer standing basically right in front of him…. My guess is he’s just not the brightest of people.” As we have seen, not noticing something right in front of you (or along your path, as in this case or the Kenny Conley incident) is a common occurrence that has nothing to do with an individual’s intelligence, or lack thereof. Hastings’s reaction, though, has everything to do with the illusion of attention. What was perhaps unintelligent about Robbins’s plan—like McArthur Wheeler’s—was attempting the robbery with no disguise in front of a surveillance camera. See “Foiled Robbery Attempt Leads to Police Chase,” KATV-7, September 6, 2007 (www.katv.com/news/stories/0907/453127.html); the security video is available at “Police Say Tape Shows Attempted Bank Robbery in Front of Uniformed Cop,” USA Today On Deadline blog, September 7, 2007 (blogs.usatoday.com/ondeadline/2007/09/police-say-tape.html). Several of the examples of stupid crimes that we have mentioned in this section come from “The Top Ten Stupid Criminals of 2007,” Neatorama blog (www.neatorama.com/2007/12/18/the-top-ten-stupid-criminals-of-2007/), which has links to original news sources.
10. Research about judgments of beauty is reviewed in N. Etcoff, Survival of the Prettiest: The Science of Beauty (New York: Doubleday, 1999).
11. These percentages were constructed from additional information provided by Justin Kruger (personal communication, January 24, 2009). For the top quartile of subjects on the sense of humor test, the correlation between subject ratings of funniness and comedian ratings was r = .57; for the bottom quartile it was r = −.13 (in each case the correlation is across jokes).
12. Here and in similar contexts in this book, when we refer to the “average” person or someone performing better than “average,” we are using the term average in an informal rather than a statistical sense. Although average in a statistical sense refers to the mean value, we are referring to the median. The median student has a better sense of humor than 50 percent of the other students and a worse sense of humor than the other 50 percent. If sense of humor is symmetrically distributed about a mean value—and we have no reason to suspect otherwise—then the mean student is the median student as well. When the distribution is biased in one direction or the other, the mean and median may differ, but in the examples we discuss, they typically will be close to each other.
13. We also used regre
ssion analysis to show that a player’s chess rating is the single best predictor of chess overconfidence, beating out age, education level, years playing the game, years playing competitively, and the number of months since the player’s last tournament (i.e., how “in practice” the player was at the time of our survey). For example, rating explains 23 percent of the variance in overconfidence, while sex, age, and years of education together only explain an additional 10 percent.
14. They chose reasoning as a skill to improve because it’s harder to improve a person’s sense of humor (especially if that person didn’t laugh at the joke about the child making God cry). Educational psychologist Diane Horgan raises the intriguing alternative that a better understanding of one’s skill level is not necessarily the result of greater skill. Instead, the causation can also run in the other direction: Realistically understanding your skill level might help you improve by enabling you to adjust your expectations, properly gauge feedback, identify your strengths and weaknesses, and so on. If you are overconfident in your ability, you may also be less motivated to improve it. After all, you “know” that you are already good, so you don’t need to practice more. These considerations should give pause to advocates of increasing children’s self-esteem as a salve for educational underachievement. See D. Horgan, “Children and Chess Expertise: The Role of Calibration,” Psychological Research 54 (1992): 44–50.
The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us Page 31