38. people learn better after a quiet stroll: Marc G. Berman et al., "The Cognitive Benefits of Interacting with Nature," Psychological Science 19, no. 12 (2008): 120712. See also Stephen Kaplan and Marc Berman, "Directed Attention as a Common Resource for Executive Functioning and Self-Regulation," Perspectives on Psychological Science 5, no. 1 (2010): 4357.

39. Another study, of 38,000 knowledge workers: Davis et al., "The Physical Environment of the Office."

40. Even mult.i.tasking ... a myth: John Medina, Brain Rules (Seattle, WA: Pear Press, 2008), 87.

41. Backbone Entertainment: Mike Mika, interview with the author, July 12, 2006.

42. Reebok International: Kimberly Blanton, "Design It Yourself: Pleasing Offices Laid Out by the Workers Who Use Them Can Be a Big Advantage When Companies Compete for Talent," Boston Globe, March 1, 2005.

43. For ten years, beginning in 2000: TEDx Midwest Talk, October 15, 2010. Also, e-mail to the author, November 5, 2010.

44. Kafka, for example: Anthony Storr, Solitude: A Return to the Self (New York: Free Press, 2005), 103.

45. considerably more cheerful Theodor Geisel: Judith Morgan and Neil Morgan, Dr. Seuss and Mr. Geisel: A Biography (New York: DaCapo, 1996).

46. legendary advertising man Alex Osborn: Alex Osborn, Your Creative Power (W. Lafayette, IN: Purdue University Press, 1948).

47. group brainstorming doesn't actually work: Marvin D. Dunnette et al., "The Effect of Group Partic.i.p.ation on Brainstorming Effectiveness for Two Industrial Samples," Journal of Applied Psychology 47, no. 1 (1963): 3037.

48. some forty years of research: See, for example, Paul A. Mongeau and Mary Claire Morr, "Reconsidering Brainstorming," Group Facilitation 1, no. 1 (1999): 14. See also Karan Girotra et al., "Idea Generation and the Quality of the Best Idea," Management Science 56, no. 4 (April 2010): 591605. (The highest level innovation comes from a hybrid process in which people brainstorm on their own before sharing ideas with colleagues.)

49. "business people must be insane": Adrian Furnham, "The Brainstorming Myth," Business Strategy Review 11, no. 4 (2000): 2128.

50. Groups brainstorming electronically: Paul Mongeau and Mary Claire Morr, "Reconsidering Brainstorming."

51. The same is true of academic research: Charlan Nemeth and Jack Goncalo, "Creative Collaborations from Afar: The Benefits of Independent Authors," Creativity Research Journal 17, no. 1 (2005): 18.

52. usually believe that their group performed much better: Keith Sawyer, Group Genius: The Creative Power of Collaboration (New York: Basic Books, 2007), 66.

53. the fear of public humiliation: Susan K. Opt and Donald A. Loffredo, "Rethinking Communication Apprehension: A Myers-Briggs Perspective," Journal of Psychology 134, no. 5 (2000): 55670.

54. two NCAA basketball teams: James C. Moore and Jody A. Brylinsky, "Spectator Effect on Team Performance in College Basketball," Journal of Sport Behavior 16, no. 2 (1993): 77.

55. behavioral economist Dan Ariely: Dan Ariely, "What's the Value of a Big Bonus?" New York Times, November 19, 2008.

56. Gregory Berns: The Solomon Asch and Gregory Berns experiments are described in Gregory Berns, Iconoclast: A Neuroscientist Reveals How to Think Differently (Boston, MA: Harvard Business Press, 2008), 5981. See also Sandra Blakeslee, "What Other People Say May Change What You See," New York Times, June 28, 2005. And see Gregory S. Berns et al., "Neurobiological Correlates of Social Conformity and Independence During Mental Rotation," Biological Psychiatry 58 (2005): 24553.

57. heightened activation in the amygdala: In fact, in some iterations of the experiment, where the volunteers played with a group of computers rather than with a group of people, their amygdalae stayed quiet even when they disagreed with the computers. This suggests that people who don't conform suffer not so much the fear of being wrong as the anxiety of being excluded from the group.

58. face-to-face interactions create trust: Belinda Lus...o...b.., "Why E-Mail May Be Hurting Off-Line Relationships," Time, June 22, 2010.

59. population density is correlated with innovation: Jonah Lehrer, "How the City Hurts Your Brain," Boston Globe, January 2, 2009.

60. creating "flexible" open plans: Davis et al., "The Physical Environment of the Office."

61. At Pixar Animation Studios: Bill Capodagli, "Magic in the Workplace: How Pixar and Disney Unleash the Creative Talent of Their Workforce," Effectif, September/October 2010: 4345.

62. Similarly, at Microsoft: Mich.e.l.le Conlin, "Microsoft's Meet-My-Mood Offices," Bloomberg Businessweek, September 10, 2007.

CHAPTER 4: IS TEMPERAMENT DESTINY?

A general note on this chapter: Chapter 4 discusses the psychologist Jerome Kagan's work on high reactivity, which some contemporary psychologists would consider to lie at the intersection of introversion and another trait known as "neuroticism." For the sake of readability, I have not elucidated that distinction in the text.

1. For one of those studies, launched in 1989: This study is discussed at length in Jerome Kagan and Nancy Snidman, The Long Shadow of Temperament (Cambridge, MA: Harvard University Press, 2004).

2. "Carl Jung's descriptions of the introvert and extrovert": Ibid., 218.

3. reserved Tom and extroverted Ralph: Jerome Kagan, Galen's Prophecy (New York: Basic Books, 1998), 15861.

4. Some say that temperament is the foundation: See http://www.selfgrowth.com/articles/Warfield3.html.

5. potent organ: Kagan and Snidman, The Long Shadow of Temperament, 10.

6. When the Frisbee looks like it's headed straight for your nose: This image comes from an online video with Joseph Ledoux, a scientist at NYU who studies the neural basis of emotions, especially fear and anxiety. See "Fearful Brain in an Anxious World," Science & the City, http://www.nyas.org/Podcasts/Atom.axd (accessed November 20, 2008).

7. "alert attention": Elaine N. Aron, Psychotherapy and the Highly Sensitive Person (New York: Routledge, 2010), 14.

8. They literally use more eye movements: Various studies have doc.u.mented these tendencies in high-reactive children. See, for example, Jerome Kagan, "Reflection-Impulsivity and Reading Ability in Primary Grade Children," Child Development 363, no. 3 (1965): 60928. See also Ellen Siegelman, "Reflective and Impulsive Observing Behavior," Child Development 40, no. 4 (1969): 121322. These studies use the term "reflective" rather than "high-reactive," but it's a safe bet that they're talking about the same group of children. Siegelman describes them as "preferring low-risk situations generally but choosing harder, more solitary intellectual tasks ... less motorically active, and more cautious" (p. 1214). (Similar studies have been done on adults; see chapters 6 and 7.)

9. High-reactive kids also tend to think and feel deeply: Elaine Aron, The Highly Sensitive Child: Helping Our Children Thrive When the World Overwhelms Them (New York: Broadway Books), 2002.

10. If a high-reactive toddler breaks another child's toy: See the studies by Grazyna Kochanska referred to in chapter 6.

11. how a group of kids should share a coveted toy: Winifred Gallagher (quoting Kagan), "How We Become What We Are." The Atlantic Monthly, September 1994.

12. blue eyes, allergies, and hay fever ... thin body and narrow face: Kagan, Galen's Prophecy, 16061.

13. Take Disney movies: Ibid., 161.

14. extroversion and introversion are physiologically: David G. Winter, Personality: a.n.a.lysis and Interpretation of Lives (New York: McGraw-Hill, 1996), 51116.

15. 40 to 50 percent heritable: Thomas J. Bouchard Jr. and Matt McGue, "Genetic and Environmental Influences on Human Psychological Differences," Journal of Neurobiology 54 (2003): 45.

16. n.a.z.i eugenics and white supremacism: This has been written about in various places including, for example, Peter D. Kramer, Listening to Prozac (New York: Penguin, 1993), 150.

17. "I have been dragged, kicking and screaming": Gallagher (quoting Kagan), "How We Become What We Are."

18. The publication of his early findings: Kramer, Listening to Prozac, 154.

19. Kagan ushers me inside: I conducted a series of interviews with Jerome Kagan between 2006 and 2010.

20. describes himself as having been an anxious: Jerome Kagan, An Argument for Mind (New Haven, CT: Yale University Press, 2006), 4, 7.