Read The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us Online
Authors: Christopher Chabris,Daniel Simons
30.
Information about Eric Mangini’s coaching career from Wikipedia,
en.wikipedia.org/wiki/Eric_Mangini
(accessed June 16, 2009). Of course, it would be wrong to conclude that adding Mozart caused his team’s decline—beware the illusion of cause! Most likely it had no effect whatsoever.
31.
For a discussion of the effects of hypnosis on memory accuracy (and confidence), see J. F. Kihlstrom, “Hypnosis, Memory and Amnesia,”
Philosophical Transactions of the Royal Society of London B
352 (1997): 1727–1732.
32.
Even though people aren’t well-informed about the reality of hypnosis and memory, the legal system does look askance at witnesses whose memory has been hypnotically
enhanced, or who request hypnosis to help them remember. Recall Kenny Conley, the Boston cop who was convicted of perjury and obstruction of justice for his testimony that he never saw Michael Cox at the fence. A witness’s request to be hypnotized to improve his memory was at the core of the technicality that got his conviction reversed—the request undermined the witness’s credibility, and the prosecution failed to disclose it to the defense.
33.
After an exhaustive search, Barry Beyerstein of Simon Fraser University wrote, “I confess that I have been frustrated in my attempts to unearth the ultimate source of the 10% myth … there is little doubt that the primary disseminators (not to mention beneficiaries) of the 10% myth have been the touts and boosters in the ranks of the self-improvement industry, past and present.” See B. L. Beyerstein, “Whence Cometh the Myth That We Only Use 10% of Our Brains?” in
Mind Myths: Exploring Popuhr Assumptions About the Mind and Brain
, ed. S. Della Salla, 3–24 (Chichester, UK: Wiley, 1999).
34.
E. B. Titchener, “The ‘Feeling of Being Stared At,’”
Science
8 (1898): 895–897.
35.
See J. E. Coover, “The Feeling of Being Stared At,”
The American Journal of Psychology
24 (1913): 570–575. Our survey result replicates laboratory studies conducted by Jane Cottrell and Gerald Winer showing that college students as well as children believe that they can feel the stares of unseen others. See J. E. Cottrell, G. A. Winer, and M. C. Smith, “Beliefs of Children and Adults About Feeling Stares of Unseen Others,”
Developmental Psychology
32 (1996): 50–61.
36.
Some promoters of paranormal phenomena still argue in favor of the idea that people can perceive the stares of others, typically attributing the effect to mysterious effects in quantum mechanics. The methods are often suspect, and none of the studies have been published in mainstream scientific journals. As was the case for the Mozart effect, proponents of the idea that people can feel the stares of others often appeal to other studies replicating the effect, but those other results are not published in mainstream journals. For a discussion by a proponent of these effects, see D. Radin,
Entangled Minds
(New York: Paraview Press, 2006), 125–130. For critiques of their evidence, see M. Shermer, “Rupert’s Resonance,”
Scientific American
, November 2005 (
www.scientificamerican.com/article.cfm?id=ruperts-resonance
); D. F. Marks and J. Colwell, “The Psychic Staring Effect: An Artifact of Pseudo Randomization,”
Skeptical Inquirer
, September/October 2000 (
www.csicop.org/si/show/psychic_staring_effect_an_artifact_of
_pseudo_randomization/
). Note that we are not saying that what is published in reputable scientific journals is always correct, or that what gets shut out of those journals must be false. There are fads, fashions, and judgment calls in science, and our own papers are not always published in the most prestigious venues (even if they should be!). But for any given phenomenon, if no mainstream scientific journals will publish it, there’s an excellent chance it is not based on solid, replicable scientific evidence.
37.
W. B. Key,
Subliminal Seduction
(New York: Prentice Hall, 1973). The Vicary experiment is described on pages 22–23, and the “man” experiment is described on pages 29–30.
38.
On page 30 of Key’s book, the raw data from this experiment are presented in table form. We used his data to calculate that the size of the difference between the control and the subliminal message conditions was large: approximately one standard deviation. The probability that this difference could have arisen just due to chance was anastonishingly
small .0000000001—in other words, it likely was too good to be true. The scientific evidence for subliminal perception, to the extent that it meets rigorous standards and can be reproduced reliably, typically shows small effects, mostly in the speed with which people can respond. And the effects tend to be short-lived. There is still debate in the scientific literature on whether this sort of perception in the absence of awareness even exists at all. For a discussion of some of the challenges involved in demonstrating subliminal perception, see D. Hannula, D. J. Simons, and N. Cohen, “Imaging Implicit Perception: Promise and Pitfalls,”
Nature Reviews Neuroscience
6 (2005): 247–255.
39.
The best account of the truth behind Vicary’s “experiment” is found in this article: A. R. Pratkanis, “Myths of Subliminal Persuasion: The Cargo-Cult Science of Subliminal Persuasion,”
Skeptical Inquirer
16 (1992): 260–72.
40.
See Hannula et al., “Imaging Implicit Perception.” The debate is over what it means to say that something was not consciously perceived, and the methods used to assess precisely how much people are aware of. Most scientists, even those who are proponents of the idea that subliminal perception is a robust phenomenon, agree that any effects of the meaning of an unseen stimulus on cognition will tend to be fairly small, and most doubt that subliminal stimuli can persuade us to do something we wouldn’t otherwise do.
41.
A recent article has made an even stronger claim than the original one made by Vicary. This study showed that subliminally flashing the Israeli flag led Israeli subjects to substantially change their strongly held views on Palestinian statehood and settlements in Gaza. Both those who strongly opposed statehood and those who favored it moderated their views, becoming indistinguishable from each other. Even more amazing, the subliminal flags changed whom the subjects voted for, again in the direction of moderation, this time weeks after the study! To us, this study illustrates how readily people will accept what are fantastical claims when they involve the release of untapped potential to change our minds. The mechanism proposed in the paper, that seeing a flag would implicitly lead to more centrist views, fits only one explanation, generated after seeing the results. It seems more plausible to us that seeing a flag, if it has any effect at all, should make people’s views more extreme. Most people believe themselves to be patriotic, and seeing a flag should only strengthen their existing views; it should not cause them to become more centrist. Although the result might be legitimate and replicable, given the ease with which we can succumb to the illusion of untapped potential, we think skepticism is warranted in the face of such a startling finding. It is hard to imagine such a minimal experience changing someone’s sincere views so radically, especially considering that they are exposed to so many more direct attempts at persuasion. The original study is R. R. Hassin, M. J. Ferguson, D. Shidlovski, and T. Gross, “Subliminal Exposure to National Flags Affects Political Thought and Behavior,”
Proceedings of the National Academy of Sciences
104 (2007): 19757–19761.
42.
A. G. Greenwald, E. R. Spangenberg, A. R. Pratkanis, and J. Eskenazi, “Double-Blind Tests of Subliminal Self-Help Audiotapes,”
Psychological Science
2 (1991): 119–122. According to this rigorous study by four research psychologists, these recordings do appear to induce nonspecific placebo effects, because their listeners use them desiring and expecting to improve their mental function. They also leave some of their users with an illusion of having received the specific benefits sought, even when they haven’t.
43.
B. Mullen et al., “Newscasters’ Facial Expressions and Voting Behavior: Can a Smile Elect a President?”
Journal of Personality and Social Psychology
51 (1986): 291–295.
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.