The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us

by Christopher Chabris

  44. See M. Gladwell, The Tipping Point (New York: Little, Brown, 2000), 74–80. It’s also worth mentioning that the evidence in the original study supporting the existence of an association between television news viewing and voting was fairly minimal. The percentages were based on data from fewer than forty people per town, and in some cases, only a handful of people watched ABC. If only five people watched ABC, then a shift of 20 percent represents just one viewer. In a reanalysis of the data from the original study using a standard statistical test known as a chi-square, we found that none of the differences in voting patterns were statistically significant. In other words, there might not even have been a reliable association between viewing preferences and voting patterns, making the causal claim that Peter Jennings influenced voting just by smiling even less likely. In the modern era of polling, sample sizes to make claims like those in the paper would need to be at least an order of magnitude larger.

  45. Transcribed from a Flash version of the advertisement on Nintendo’s Brain Age website, www.brainage.com/launch/ontv.jsp?video=tvspot (accessed June 12, 2009).

  46. From Nintendo’s consolidated financial statements dated May 7, 2009, www.nintendo.com/corp/report/3QEnglishFinancial.pdf (accessed June 12, 2009).

  47. www.focusmm.co.uk/shop/Brain-Trainer-pr-1190.html (accessed June 15, 2009). Immediately after this claim, the website includes a footnote disclaimer that states, “Focus Multimedia and Mindscape are not qualified to offer medical advice. These exercises have been designed for recreational purposes only. No medical claims are made for these exercises, express or implied.” Essentially, the site disclaims what it just claimed. This tactic is not at all unusual for materials promoting brain-training software. British consumer organization Which? recently reviewed a number of brain-training programs and evaluated their claims, www.which.co.uk/advice/brain-training/index.jsp (accessed June 15, 2009).

  48. As one example, the Real Age website claims that it is possible to quantify someone’s brain age and that with the right activities, you can turn back the clock by a measurable number of years, www.realage.com/ralong/entry4.aspx?cbr=GGLE806-gclid=CNGY5MG1qJsCFQJvswodCF-YDA (accessed June 26, 2009). Neither claim is even testable.

  49. For example, see T. A. Salthouse, “The Processing-Speed Theory of Adult Age Differences in Cognition,” Psychological Review 103 (1996): 403–428.

  50. Statistics are from the official International Chess Federation (FIDE) records, ratings.fide.com/top.phtml?list=men (accessedJune 17, 2009).

  51. For a recent review of cognitive-training interventions and other correlational studies, see C. Hertzog, A. F. Kramer, R. S. Wilson, and U. Lindenberger, “Enrichment Effects on Adult Cognitive Development: Can the Functional Capacity of Older Adults Be Preserved and Enhanced?” Psychological Science in the Public Interest 9 (2009): 1–65.

  52. The results of this study and later follow-up analyses and longitudinal studies are reported in the following articles: K. Ball et al., “Effects of Cognitive Training Interventions with Older Adults: A Randomized Controlled Trial,” JAMA 288 (2002): 2271–2281; S. L. Willis et al., “Long-Term Effects of Cognitive Training on Everyday Functional Outcomes in Older Adults,” JAMA 296 (2006): 2805–2814; and F. D. Wolinsky, F. W. Unverzagt, D. M. Smith, R. Jones, A. Stoddard, and S. L. Tennstedt, “The ACTIVE Cognitive Training Trial and Health-Related Quality of Life: Protection That Lasts for 5 Years,” Journal of Gerontology 61A (2006): 1324–1329.

  53. One exception to this limited transfer comes from a specific training technique known as variable priority training. In essence, variable priority training focuses less on enhancing the individual components of a task than on improving your ability to allocate resources to each of them efficiently—it trains your ability to multitask. Although transfer is still limited, in most cases, to other laboratory tasks, the trained abilities are more general than the specific task learned. For a discussion of this and other training methods, see Hertzog et al., “Enrichment Effects on Adult Cognitive Development.” See also A. F. Kramer, J. Larish, T. Weber, and L. Bardell, “Training for Executive Control: Task Coordination Strategies and Aging,” in Attention and Performance XVII, ed. D. Gopher and A. Koriet, 617–652 (Cambridge, MA: MIT Press, 1999).

  54. T. A. Salthouse, “Mental Exercise and Mental Aging: Evaluating the Validity of the ‘Use It or Lose It’ Hypothesis,” Perspectives on Psychological Science 1 (2006): 68–87.

  55. The student trained for more than two hundred hours over the course of twenty months. His initial digit span was the more typical seven items. See K. A. Ericsson, W. G. Chase, and S. Faloon, “Acquisition of a Memory Skill,” Science 208 (1980): 1181–1182.

  56. A. D. de Groot, Thought and Choice in Chess (The Hague: Mouton, 1965); W. G. Chase and H. A. Simon, “Perception in Chess,” Cognitive Psychology 4 (1973): 55–81; W. G. Chase and H. A. Simon, “The Mind’s Eye in Chess,” in Visual Information Processing, ed. W. G. Chase, 215–281 (New York: Academic Press, 1973). Herbert Simon was a political scientist by training, but he became known as one of the most influential computer scientists and cognitive psychologists.

  57. Ericsson et al., “Acquisition of a Memory Skill.”

  58. C. F. Chabris and E. S. Hearst, “Visualization, Pattern Recognition, and Forward Search: Effects of Playing Speed and Sight of the Position on Grandmaster Chess Errors,” Cognitive Science 27 (2003): 637–648. Eliot Hearst has written, with John Knott, the definitive book on all aspects of blindfold chess: Blindfold Chess: History, Psychology, Techniques, Champions, World Records, and Important Games (Jefferson, NC: McFarland, 2009).

  59. There are some correlational studies showing that children who play chess do better academically than children who do not, but they do not demonstrate that learning chess causes you to improve in other areas. (Perhaps smarter kids are more likely to be interested in chess.) For example, see K. van Delft, “Chess as a Subject in Elementary School,” unpublished report, University of Amsterdam, 1992. No experimental studies on this question have been published in quality journals; the best of these may be “Chess and Cognitive Development,” an unpublished 1976 doctoral dissertation by Johan Christiaen of Rijksuniversiteit Gent, Belgium. Christiaen randomly assigned twenty fifth-graders to chess instruction and twenty to a control group and found that the chess group did better on some tests of cognitive development.

  60. C. S. Green and D. Bavelier, “Action Video Game Modifies Visual Selective Attention,” Nature 423 (2003): 534–537. The name “Useful Field of View” is a trademark of Visual Awareness Research Group, Inc.

  61. From an interview Dan conducted with Walter Boot on May 14, 2009.

  62. See R. Li, U. Polat, W. Makous, and D. Bavelier, “Enhancing the Contrast Sensitivity Function Through Action Video Game Training,” Nature Neuroscience 12 (2009): 549–551. As in the original study, the control group in this experiment (this time, practicing a Sims game) showed no improvements the second time it was tested. In this case, that’s not terribly surprising, because the task measures a basic aspect of visual processing. It is impressive that the contrast sensitivity advantages persisted even months after training. Where the original studies focused on higher-level cognitive benefits, some of which might be attributable to learned strategies rather than changes in basic abilities, these newer studies focus on basic properties of the visual system. It’s harder to see how strategies could influence these measures.

  63. See C. S. Green and D. Bavelier, “Action-Video-Game Experience Alters the Spatial Resolution of Attention,” Psychological Science 18 (2007): 88–94. Again, the control group showed no improvements at all upon retesting.

  64. A potential danger any time a study is conducted using a large battery of cognitive tasks is that some performance differences are likely to prove statistically significant by chance. These additional studies report only one or two outcome measures tested before and after thirty or more hours of training. It’s not clear whether other measures were tried but showed no differences, s
o additional replications are needed.

  65. J. Feng, I. Spence, and J. Pratt, “Playing an Action Video Game Reduces Gender Differences in Spatial Cognition,” Psychological Science 18 (2007): 850–855. The sex differences were based on just seven women and three men in each training group, so it will be important to replicate this finding with a larger sample.

  66. C. Basak, W. R. Boot, M. W. Voss, and A. F. Kramer, “Can Training in a Real-Time Strategy Video Game Attenuate Cognitive Decline in Older Adults?” Psychology and Aging 23 (2008): 765–777.

  67. Interestingly, in Boot’s study with college students as subjects, training on Rise of Nations did not lead to differential improvements.

  68. W. R. Boot, A. F. Kramer, D. J. Simons, M. Fabiani, and G. Gratton, “The Effects of Video Game Playing on Attention, Memory, and Executive Control,” Acta Psychologica 129 (2008): 387–398.

  69. Boot’s study showed a comparable amount of improvement to that shown by Green and Bavelier for two of the transfer tasks (the attentional blink and the functional field of view), but Boot’s found no significant improvement for any of the groups in the enumeration task, whereas Green and Bavelier showed improvements just for the videogame training group.

  70. At least one other recent study has failed to replicate part of the original result as well, although not the training component. The following paper did not find differences between expert and novice video-game players: K. Murphy and A. Spencer, “Playing Video Games Does Not Make for Better Visual Attention Skills,” Journal of Articles in Support of the Null Hypothesis 6, no. 1 (2009).

  71. Quotes are from an interview Dan conducted with Walter Boot on May 11, 2009.

  72. The same caveat applies to studies about a topic related to the Mozart effect: the idea that musicians have better cognitive skills (such as better verbal memory) than nonmusicians. This difference is often attributed to their music training, but it could be a so-called “Hawthorne effect”—the simple consequence of knowing you are being singled out and expected to have better performance. Or it could result from some difference between the musicians and nonmusicians that was present before the music training started.

  73. For an engrossing presentation of this claim, see Steven Johnson’s Everything Bad Is Good for You (New York: Riverhead, 2005). Johnson’s book argues convincingly that current television programs and video games are much more complex, and require greater levels of mental effort to process, than the most popular shows and games of the 1970s and 1980s. But it offers no decisive evidence for its provocative thesis that the greater complexity of TV and games is causing an increase in intelligence or social ability. For support, Johnson does cite the Flynn effect, a large worldwide increase in measured general cognitive ability during the twentieth century, but this upward trend began long before video games were even invented, and in any case—we are sorry for sounding like a broken record on this point—a correlation or chronological connection does not prove causation. Many other things about society and daily life have changed in the last several decades besides the invention of HBO dramas, reality TV, and massively multiplayer online video games. Johnson grapples with these issues but cannot wrestle them down—because no one can.

  74. From the Nintendo Brain Age website, www.brainage.com/launch/training.jsp (accessed June 12, 2009).

  75. See Hertzog et al., “Enrichment Effects on Adult Cognitive Development.”

  76. A. F. Kramer et al., “Ageing, Fitness and Neurocognitive Function,” Nature 400 (1999): 418–419.

  77. S. Colcombe and A. F. Kramer, “Fitness Effects on the Cognitive Function of Older Adults: A Meta-Analytic Study,” Psychological Science 14 (2003): 125–130. See also A. F. Kramer and K. I. Erickson, “Capitalizing on Cortical Plasticity: Influence of Physical Activity on Cognition and Brain Function,” Trends in Cognitive Sciences 11 (2007): 342–348.

  78. S. J. Colcombe, K. I. Erickson, P. E. Scalf, J. S. Kim, R. Prakash, E. McAuley, S. Elavsky, D. X. Marquez, L. Hu, and A. F. Kramer, “Aerobic Exercise Training Increases Brain Volume in Aging Humans,” Journal of Gerontology: Medical Sciences 61 (2006): 1166–1170.

  Conclusion: The Myth of Intuition

  1. Actual leadership profiles like this one are dissected by Phil Rosenzweig in his excellent book The Halo Effect … and the Eight Other Business Delusions That Deceive Managers (New York: Free Press, 2007); see especially pp. 18–49. Although we have picked on business journalists in this example, we are not intentionally singling them out as subject to these illusions. To be crystal clear: Everyone is subject to everyday illusions, including ourselves.

  2. For more on the role of fluency and mistaken attributions about our own thoughts, see D. M. Oppenheimer, “The Secret Life of Fluency,” Trends in Cognitive Sciences 12 (2008): 237–241; N. Schwartz, “Metacognitive Experiences in Consumer Judgment and Decision Making,” Journal of Consumer Psychology 14 (2004): 332–348; and D. Kahneman and S. Frederick, “Representativeness Revisited: Attribute Substitution in Intuitive Judgment,” in Heuristics and Biases, ed. T. Gilovich, D. Griffin, and D. Kahneman, 49–81 (Cambridge: Cambridge University Press, 2002).

  3. The fast, automatic processes are often known as “System 1” and the slow, reflective processes as “System 2,” a useful distinction first introduced by Steven A. Sloman, given these names by Keith E. Stanovich and Richard F. West, and advocated in an influential paper by Daniel Kahneman and Shane Frederick. All of these papers are reprinted in Gilovich, Griffin, and Kahneman, Heuristics and Biases. For discussion of why the mind is designed this way, the following books all offer interesting perspectives: S. Pinker, How the Mind Works (New York: Norton, 1997); G. Marcus, Kluge: The Haphazard Construction of the Human Mind (New York: Houghton Mifflin, 2008); G. Gigerenzer, Gut Feelings: The Intelligence of the Unconscious (New York: Viking, 2007); and M. Piattelli-Palmarini, Inevitable Illusions: How Mistakes of Reason Rule Our Minds (New York: Wiley, 1994).

  4. C. Kennedy, “ABB: Model Merger for the New Europe,” Long Range Planning 23, no. 5 (1992): 10–17 (as cited by Rosenzweig, The Halo Effect). We are commenting on how Barnevik’s management style was portrayed in the press, not on Barnevik himself.

  5. Information on the Iridium project comes from Chapter 6 of P. B. Carroll and C. Mui, Billion Dollar Lessons: What You Can Learn from the Most Inexcusable Business Failures of the Last 25 Years (New York: Portfolio, 2008).

  6. Harry Buxton-Forman, who had vouched for Wise’s discovery, had expertise in the printing process and appeared to have collaborated on the scam with Wise.

  7. Information on the Thomas J. Wise fraud comes from these sources: M. Jones, P. Craddock, and N. Barker, Fake? The Art of Deception (Berkeley: University of California Press, 1990); J. Carter and G. Pollard, An Enquiry into the Nature of Certain XIXth Century Pamphlets (London: Constable, 1934); and W. B. Todd, Thomas J. Wise: Centenary Studies (Austin: University of Texas Press, 1959).

  8. M. Gladwell, Blink: The Power of Thinking Without Thinking (New York: Little, Brown, 2005), 3–8. Gladwell doesn’t actually use the words intuition or intuitive much in Blink, but that is more a matter of word choice than of intended meaning. He argues that “there can be as much value in the blink of an eye as in months of rational analysis” (p. 17). Gladwell presents numerous examples of high-quality “snap” decisions made in the blink of an eye, without the benefit of deliberation—that is, decisions made intuitively.

  9. Many readers of Blink take Gladwell’s point about the power of rapid cognition to heart without fully appreciating the way he qualifies his claims. Gladwell notes that it is important to understand when intuitions will and will not be useful, and he provides examples in which intuitions fail: Warren Harding looked presidential, but turned out to be a bad president; musicians are selected more fairly when they are heard performing behind a screen than when the judges can see them play; New York City police officers rapidly fired forty-one bullets at Amadou Diallo on a cold Bronx night in 1999. Blink does give more weight to the successes of
intuition than to its failures, often attributing the failures to other situational factors such as excessive stress or pressure. But it seems just as reasonable to think that rapid cognition should be most effective precisely when careful deliberation is impossible (due to stress or time pressure).

  10. T. D. Wilson and J. W. Schooler, “Thinking Too Much: Introspection Can Reduce the Quality of Preferences and Decisions,” Journal of Personality and Social Psychology 60 (1991): 181–192.

  11. J. W. Schooler and T. Y. Engstler-Schooler, “Verbal Overshadowing of Visual Memories: Some Things Are Better Left Unsaid,” Cognitive Psychology 22 (1990): 36–71. This article points out some earlier literature on the effect, going back to E. Belbin, “The Influence of Interpolated Recall Upon Recognition,” Quarterly Journal of Experimental Psychology 2 (1950): 163–169.

  12. In Blink, Malcolm Gladwell described a similar experiment and explained the verbal overshadowing effect this way: “Your brain has a part (the left hemisphere) that thinks in words, and a part (the right hemisphere) that thinks in pictures, and what happened as you described the face in words was that … your thinking was bumped from the right to the left hemisphere” (pp. 119–120). As we pointed out in Chapter 6, the idea that the two halves of our brain have radically distinct, nonoverlapping capabilities and modes of thought (words versus pictures) is part and parcel of the false belief that the pictorial and holistic right hemisphere is routinely suppressed by the verbal and analytical left, and that we can think much better by releasing its hidden potential.

  13. Chabris and Hearst, “Visualization, Pattern Recognition, and Forward Search.”

  14. From Woody Allen’s 1960s stand-up comedy, recorded on the album Standup Comic, released by Casablanca Records in 1979. The quote is from the final track, “Summing Up.”

  Copyright © 2010 by Christopher F. Chabris and Daniel J. Simons