The Art of Thinking Clearly

by Rolf Dobelli

  Roy Baumeister, “Ego Depletion and Self-Control Failure: An Energy Model of the Self’s Executive Function,” Self and Identity 1, no. 2 (April 1, 2002): 129–36.

  Kathleen D. Vohs, Roy F. Baumeister, Jean M. Twenge, Brandon J. Schmeichel, Dianne M. Tice, and Jennifer Crocker, “Decision Fatigue Exhausts Self-Regulatory Resources—But So Does Accommodating to Unchosen Alternatives,” Working paper, 2005.

  George Loewenstein, Daniel Read, and Roy Baumeister, Time and Decision: Economic and Psychological Perspectives on Intertemporal Choice (New York: Russell Sage Foundation, 2003), 208.

  After the hard slog through the supermarket, consumers suffer decision fatigue. Retailers capitalize on this and place impulse buys, such as gum and candy, right next to cashiers—just before the finishing line of the decision marathon. See: John Tierney, “Do You Suffer from Decision Fatigue?,” New York Times Magazine, August 17, 2011.

  When to present it to your CEO? The best time is eight a.m. The CEO will be relaxed after a good night’s sleep, and after breakfast his blood sugar level will be high—all perfect for making courageous decisions.

  CONTAGION BIAS

  Contagion bias is also called the “contagion heuristic.”

  The one-line summary of the contagion bias: “Once in contact, always in contact.”

  Thomas Gilovich, Dale Griffin, and Daniel Kahneman (eds.), Heuristics and Biases: The Psychology of Intuitive Judgment (Cambridge, UK: Cambridge University Press, 2002), 212.

  See also the Wikipedia entry for the “Peace and Truce of God,” accessed October 21, 2012.

  Philip Daileader, The High Middle Ages (Chantilly, VA: The Teaching Company, 2001), course no. 869, lecture 3, beginning at ~26:30.

  The example with the arrows comes from Kennedy vs. Hitler in: Gilovich, Griffin, and Kahneman (eds.), Heuristics and Biases, 205. The authors of the article (Paul Rozin and Carol Nemeroff) are not talking about “contagion” but about the “law of similarity.” I have added the example of contagion heuristic, which in the broader sense deals with a penchant for magic.

  Photos of mothers: A control group that did not use photos was better at hitting the targets. Participants behaved as if the photos contained magic powers that might hurt the real subjects. In a similar experiment, photographs of either John F. Kennedy or Hitler were pasted onto the targets. Although all students were trying to shoot as accurately as possible, those who had JFK in their crosshairs fared much worse. (Ibid.)

  We do not like to move into recently deceased people’s houses, apartments, or rooms. Conversely, companies love when their new offices previously housed successful companies. For example, when milo.com moved into 165 University Avenue in Palo Alto, there was a lot of press because Logitech, Google, and PayPal all used to be in that building. As if some “good vibes” would lift the start-ups in that building. It certainly has more to do with the proximity to Stanford University.

  To calculate the number of molecules per breath: The atmosphere consists of approximately 10^44 molecules. The total atmospheric mass is 5.1x10^18 kg. Air density at sea level is about 1.2 kg/m3. According to the Avogadro constant, there are 2.7x10^25 molecules in a cubic meter of air. So, in one liter there are 2.7x10^22 molecules. On average, we breathe about seven liters of air per minute (about one liter per breath) or 3,700 cubic meters per year. Saddam Hussein “consumed” 260,000 cubic meters of air in his life. Assuming he re-inhaled approximately 10 percent of that, we have 230,000 cubic meters of “Saddam-contaminated” air in the atmosphere. Thus 6.2x10^30 molecules passed through Saddam’s lungs, which are now scattered in the atmosphere. The concentration of these molecules in the atmosphere equals 6.2x10^–14. That makes 1.7 billion “Saddam-contaminated” molecules per breath.

  See also: Carol Nemeroff and Paul Rozin, “The Makings of the Magical Mind: The Nature of Function of Sympathetic Magic,” in Karl S. Rosengren, Carl N. Johnson, and Paul L. Harris (eds.), Imagining the Impossible: Magical, Scientific, and Religious Thinking in Children (Cambridge, UK: Cambridge University Press, 2000), 1–34.

  THE PROBLEM WITH AVERAGES

  Don’t cross a river if it is (on average) four feet deep: Nassim Nicholas Taleb, The Black Swan: The Impact of the Highly Improbable (New York: Random House, 2007), 160.

  The overall median wealth per family in the United States was $109,500 in 2007. See: Wikipedia Entry on “Wealth in the United States,” accessed October 25, 2012, http://en.wikipedia.org/wiki/Wealth_in_the_United_States. Since I used individuals and not families in the example with the bus, I took 50 percent of that figure. That’s not a correct figure, since individuals who live by themselves also constitute a household in the technical sense. But the exact number doesn’t matter for the example.

  MOTIVATION CROWDING

  Bruno S. Frey, “Die Grenzen ökonomischer Anreize,” Neue Zürcher Zeitung, May 18, 2001. (Translation: “The Limits of Economic Incentives.” Bruno Frey makes the case to scientifically study intrinsic motivation instead of [mostly] monetary incentives. There is no English translation of this article.)

  This paper provides a good overview: Bruno S. Frey and Reto Jegen, “Motivation Crowding Theory: A Survey of Empirical Evidence,” Journal of Economic Surveys 15, no. 5 (2001): 589–611.

  The story with the day care center: Steven D. Levitt and Stephen J. Dubner, Freakonomics: A Rogue Economist Explores the Hidden Side of Everything (New York: William Morrow, 2005), 19.

  Ori Brafman and Rom Brafman, Sway: The Irresistible Pull of Irrational Behavior (New York: Doubleday, 2008), 131–35.

  It’s not all black and white. In certain settings, pay for performance can also have a positive effect on self-determination and task enjoyment. Robert Eisenberger, Linda Rhoades, and Judy Cameron, “Does Pay for Performance Increase or Decrease Perceived Self-Determination and Intrinsic Motivation?,” Journal of Personality and Social Psychology 77, no. 5 (1999): 1026–40.

  There are so many examples of motivation crowding, and the scientific literature is ample. Here is an example: “Every year, on a predetermined day, students go from house to house collecting monetary donations that households make to societies for cancer research, help for disabled children, and the like. Students performing these activities typically receive much social approval from parents, teachers, and other people. This is the very reason why they perform these activities voluntarily. When students were each offered one percent of the money they collected, the amount collected decreased by 36 percent.” Ernst Fehr and Armin Falk, “Psychological Foundations of Incentives,” European Economic Review 46 (May 2002): 687–724.

  TWADDLE TENDENCY

  An example of smoke screen writing: Jürgen Habermas, Between Facts and Norms: Contributions to a Discourse Theory of Law and Democracy (Cambridge, MA: MIT Press, 1998), 490.

  WILL ROGERS PHENOMENON

  Stage migration when diagnosing tumors goes even further than described in the chapter. Because stage 1 now contains so many cases, doctors adjust the boundaries between stages. The worst stage 1 patients are categorized as stage 2, the worst stage 2 patients as stage 3, and the worst stage 3 patients as stage 4. Each of these new additions raises the average life expectancy of the group. The result: Not a single patient lives longer. It appears that the therapy has helped patients, but merely the diagnosis has improved. A. R. Feinstein, D. M. Sosin, and C. K. Wells, “The Will Rogers Phenomenon—Stage Migration and New Diagnostic Techniques as a Source of Misleading Statistics for Survival in Cancer,” New England Journal of Medicine 312, no. 25 (June 1985): 1604–8.

  Further examples can be found in the excellent book: Hans-Hermann Dubben and Hans-Peter Beck-Bornholdt, Der Hund, der Eier legt: Erkennen von Fehlinformation durch Querdenken (Reinbek, Germany: Rororo Publisher, 2006), 34–235. There is no English translation of this book.

  INFORMATION BIAS

  “To bankrupt a fool, give him information.” Nassim Nicholas Taleb,
The Bed of Procrustes: Philosophical and Practical Aphorisms (New York: Random House, 2010), 4.

  The example with the three diseases: Jonathan Baron, Jane Beattie, and John C. Hershey, “Heuristics and Biases in Diagnostic Reasoning: II. Congruence, Information, and Certainty,” Organizational Behavior and Human Decision Processes 42 (1988): 88–110.

  EFFORT JUSTIFICATION

  For Aronson and Mills the effort justification is nothing but the reduction of cognitive dissonance. Elliot Aronson and Judson Mills, “The Effect of Severity of Initiation on Liking for a Group,” Journal of Abnormal and Social Psychology 59 (1959): 177–81.

  Michael I. Norton: Michael I. Norton, Daniel Mochon, and Dan Ariely, “The IKEA Effect: When Labor Leads to Love,” Journal of Consumer Psychology 22, no. 3 (July 2012): 453–60.

  THE LAW OF SMALL NUMBERS

  Daniel Kahneman uses a good example in his book Thinking, Fast and Slow (New York: Farrar, Straus and Giroux, 2011), 109–113. My story with the shoplifting rates borrows heavily from this.

  EXPECTATIONS

  In the main text, we did not cover asymmetry. Shares that exceed expectations rise, on average, by 1 percent. Shares that fall below expectations drop, on average, by 3.4 percent. See: Jason Zweig, Your Money and Your Brain (New York: Simon & Schuster, 2007), 181.

  Rosenthal effect: Robert Rosenthal and Leonore Jacobson, Pygmalion in the Classroom, expanded ed. (New York: Irvington, 1968).

  Robert S. Feldman and Thomas Prohaska, “The Student as Pygmalion: Effect of Student Expectation on the Teacher,” Journal of Educational Psychology 71, no. 4 (1979): 485–93.

  SIMPLE LOGIC

  The original paper on the CRT: Shane Frederick, “Cognitive Reflection and Decision Making,” Journal of Economic Perspectives 19, no. 4 (Fall 2005): 25–42.

  Amitai Shenhav, David G. Rand, and Joshua D. Greene, “Divine Intuition: Cognitive Style Influences Belief in God,” Journal of Experimental Psychology 141, no. 3 (August 2012): 423–28.

  FORER EFFECT

  Bertram R. Forer, “The Fallacy of Personal Validation: A Classroom Demonstration of Gullibility,” Journal of Abnormal and Social Psychology 44, no. 1 (1949): 118–23.

  This is also called the “Barnum effect.” Ringmaster Phineas T. Barnum designed his show around the motto: “a little something for everybody.”

  Joel T. Johnson, Lorraine M. Cain, Toni L. Falke, Jon Hayman, and Edward Perillo, “The ‘Barnum Effect’ Revisited: Cognitive and Motivational Factors in the Acceptance of Personality Descriptions,” Journal of Personality and Social Psychology 49, no. 5 (November 1985): 1378–91.

  D. H. Dickson and I. W. Kelly, “The ‘Barnum Effect’ in Personality Assessment: A Review of the Literature,” Psychological Reports 57 (1985): 367–82.

  The Skeptic’s Dictionary has a good entry on the Forer Effect: http://www.skepdic.com/forer.html.

  VOLUNTEER’S FOLLY

  No topic has drawn more feedback than this (previously these chapters were newspaper columns). One reader commented that it would be even better to have the birdhouses manufactured in China than to get a local carpenter to make them. The reader is right, of course, providing you subtract the environmental damage caused by the shipping. The point is that volunteer’s folly is nothing more than David Ricardo’s law of comparative advantage.

  Trevor M. Knox, “The Volunteer’s Folly and Socio-Economic Man: Some Thoughts on Altruism, Rationality, and Community,” Journal of Socio-Economics 28, no. 4 (1999): 475–92.

  AFFECT HEURISTIC

  Daniel Kahneman, Thinking, Fast and Slow (New York: Farrar, Straus and Giroux, 2011), 139–42.

  Priming the affect through smilies or frownies before judging Chinese icons: Sheila T. Murphy, Jennifer L. Monahan, and R. B. Zajonc, “Additivity of Nonconscious Affect: Combined Effects of Priming and Exposure,” Journal of Personality and Social Psychology 69, no. 4 (October 1995): 589–602.

  See also: Piotr Winkielman, Robert B. Zajonc, and Norbert Schwarz, “Subliminal Affective Priming Attributional Interventions,” Cognition and Emotion 11, no. 4 (1997): 433–65.

  How morning sun affects the stock market: David Hirshleifer and Tyler Shumway, “Good Day Sunshine: Stock Returns and the Weather,” Journal of Finance 58, no. 3 (2003): 1009–32.

  INTROSPECTION ILLUSION

  Kathryn Schulz, Being Wrong: Adventures in the Margin of Error (New York: Ecco, 2010), 104–10. I’ve adapted Schulz’s green teas story and made it into a story of a vitamin pill producer.

  Much of the introspection illusion comes down to “shallow thinking”: Thomas Gilovich, Nicholas Epley, and Karlene Hanko, “Shallow Thoughts about the Self: The Automatic Components of Self-Assessment,” in Mark D. Alicke, David A. Dunning, and Joachim I. Krueger, The Self in Social Judgment: Studies in Self and Identity (New York: Psychology Press, 2005), 67–81.

  Richard E. Nisbett and Timothy D. Wilson, “Telling More Than We Can Know: Verbal Reports on Mental Processes,” Psychological Review 84 (1977): 231–59.

  INABILITY TO CLOSE DOORS

  Dan Ariely, Predictably Irrational: The Hidden Forces That Shape Our Decisions, rev. and expanded ed. (New York: HarperCollins, 2008), chapter 9, “Keeping Doors Open,” 183–98.

  Mark Edmundson describing today’s generation of students: “They want to study, travel, make friends, make more friends, read everything (superfast), take in all the movies, listen to every hot band, keep up with everyone they’ve ever known. And there’s something else, too, that distinguishes them: They live to multiply possibilities. They’re enemies of closure. For as much as they want to do and actually manage to do, they always strive to keep their options open, never to shut possibilities down before they have to.” Mark Edmundson, “Dwelling in Possibilities,” Chronicle of Higher Education, March 14, 2008.

  NEOMANIA

  Nassim Nicholas Taleb, Antifragile: Things That Gain from Disorder (New York: Random House, 2012), 322–28.

  SLEEPER EFFECT

  Carl Hovland carried out his tests using the propaganda movie Why We Fight. The movie is available on YouTube.

  See also: Gareth Cook, “TV’s Sleeper Effect: Misinformation on Television Gains Power over Time,” Boston Globe, October 30, 2011.

  Beliefs acquired by reading fictional narratives are integrated into real-world knowledge. In: Markus Appel and Tobias Richter, “Persuasive Effects of Fictional Narratives Increase over Time,” Media Psychology 10 (2007): 113–34.

  Tarcan G. Kumkale and Dolore Albarracín, “The Sleeper Effect in Persuasion: A Meta-Analytic Review,” Psychological Bulletin 130, no. 1 (January 2004): 143–72.

  David Mazursky and Yaacov Schul, “The Effects of Advertisement Encoding on the Failure to Discount Information: Implications for the Sleeper Effect,” Journal of Consumer Research 15, no. 1 (1988): 24–36.

  Ruth Ann Weaver Lariscy and Spencer F. Tinkham, “The Sleeper Effect and Negative Political Advertising,” Journal of Advertising 28, no. 4 (Winter 1999): 13–30.

  SOCIAL COMPARISON BIAS

  Stephen M. Garcia, Hyunjin Song, and Abraham Tesser, “Tainted Recommendations: The Social Comparison Bias,” Organizational Behavior and Human Decision Processes 113, no. 2 (2010): 97–101.

  B-players hire C-players, and so on. Watch this excellent video on YouTube: Guy Kawasaki, The Art of the Start.

  By the way: Some authors succeed at mutually flattering each another, such as Niall Ferguson and Ian Morris. They continually bestow the title of “best historian” upon each other. Clever. It’s rare, a perfected art.

  PRIMACY AND RECENCY EFFECTS

  Primacy effect: Psychologist Solomon Asch scientifically investigated this in the 1940s. The example using Alan und Ben comes from him. Solomon E. Asch, “Forming Impressions of Personality,” Journal of Abnormal and Social Psychology 41, no. 3 (July 1946): 258–90.

  The example from Ala
n and Ben cited in: Daniel Kahneman, Thinking, Fast and Slow (New York: Farrar, Straus and Giroux, 2011), 82–83.

  The final ad before a film starts is the most expensive for another reason: It will reach the most people since everyone will have taken their seats by then.

  There is a myriad of research on the primacy and recency effects. Here are two papers: Arthur M. Glenberg et al., “A Two-Process Account of Long-Term Serial Position Effects,” Journal of Experimental Psychology: Human Learning and Memory 6, no. 4 (July 1980): 355–69. And: M. W. Howard and M. Kahana, “Contextual Variability and Serial Position Effects in Free Recall,” Journal of Experimental Psychology: Learning, Memory and Cognition 25, no. 4 (July 1999): 923–41.

  NOT-INVENTED-HERE SYNDROME

  Ralph Katz and Thomas J. Allen, “Investigating the Not Invented Here (NIH) Syndrome: A Look at the Performance, Tenure and Communication Patterns of 50 R&D Project Groups,” R&D Management 12, no. 1 (1982): 7–19.

  Joel Spolsky wrote an interesting blog entry contesting NIH syndrome. It’s available online under the name: In Defense of Not-Invented-Here Syndrome (in http://www.joelonsoftware.com, October 14, 2001). His theory: World-class teams should not be dependent on the developments of other teams or other companies. When developing any in-house product, you should design the central part yourself from top to bottom. This reduces dependencies and guarantees the highest quality.

  THE BLACK SWAN

  Nassim Nicholas Taleb, The Black Swan: The Impact of the Highly Improbable (New York: Random House, 2007).

  DOMAIN DEPENDENCE

  “Upon arriving at the hotel in Dubai, the businessman had a porter carry his luggage; I later saw him lifting free weights in the gym.” Nassim Nicholas Taleb, The Bed of Procrustes: Philosophical and Practical Aphorisms (New York: Random House, 2010), 75.

  Another brilliant aphorism by Taleb on the subject: “My best example of domain dependence of our minds, from my recent visit to Paris: at lunch in a French restaurant, my friends ate the salmon and threw away the skin; at dinner, at the sushi bar, the very same friends ate the skin and threw away the salmon.” Ibid., 76.