“improvise, adapt, overcome”: Michael Martel, Improvise, Adapt, Overcome: Achieve the Green Beret Way (Seattle: Amazon Digital Services, Inc., 2012).
“made mine wither”: Robert Mankoff, How About Never—Is Never Good for You?: My Life in Cartoons (New York: Henry Holt and Company, 2014), 34.
“I’ve written this book”: Syd Hoff, Learning to Cartoon (New York: Stravon Educational Press, 1966), vii.
“How could anyone do more than twenty-seven cartoons?”: Mankoff, How About Never, 38.
“I’m the funniest guy you ever met”: Bob Mankoff, cartoon editor of the New Yorker, in an interview with the author, February 10, 2015.
“I’m going to be a cartoonist”: Mankoff, interview.
“wallpaper my bathroom”: Mankoff, How About Never, 44.
“you too were one of the best”: Ibid., 46.
“I looked up all the cartoons”: Mankoff, interview.
“I had complete confidence”: Ibid.
“things never work out”: Mankoff, How About Never, 114.
301 exceptionally accomplished: Cox, “Early Mental Traits.”
“Cox’s First Ten”: Ibid., 181. Presented here in alphabetical order by last name.
“with somewhat less persistence”: Ibid., 187.
CHAPTER 5: GRIT GROWS
worth our attention: Psychologist Steve Heine has done research showing that if you think something is genetic, then you think it is “natural” and therefore the way things “should be.” For example, if you tell obese people that obesity has a genetic basis, they reduce their dieting efforts. See Ilan Dar-Nimrod and Steven J. Heine, “Genetic Essentialism: On the Deceptive Determinism of DNA,” Psychological Bulletin 137 (2011): 800–18. Perhaps people would not have such a knee-jerk reaction if they understood better that the interplay between genes and the environment is complex and dynamic. The interested reader might find the work of Elliot Tucker-Drob on this topic especially illuminating; for example, see Daniel A. Briley and Elliot M. Tucker-Drob, “Comparing the Developmental Genetics of Cognition and Personality Over the Life Span,” Journal of Personality (2015): 1–14.
150 years ago: Timothy J. Hatton and Bernice E. Bray, “Long Run Trends in the Heights of European Men, 19th–20th Centuries,” Economics and Human Biology 8 (2010): 405–13.
average is five feet ten inches: Alison Moody, “Adult Anthropometric Measures, Overweight and Obesity,” in Health Survey for England 2013, ed. Rachel Craig and Jennifer Mindell (London: Health and Social Care Information Centre, 2014).
gain of more than six inches: Hatton, “Long Run Trends.” Yvonne Schonbeck et al., “The World’s Tallest Nation Has Stopped Growing Taller: The Height of Dutch Children from 1955 to 2009,” Pediatric Research 73 (2013): 371–77.
honesty and generosity: See Eric Turkheimer, Erik Pettersson, and Erin E. Horn, “A Phenotypic Null Hypothesis for the Genetics of Personality,” Annual Review of Psychology 65 (2014): 515–40.
Ditto for IQ: Richard E. Nisbett et al., “Intelligence: New Findings and Theoretical Developments,” American Psychologist 67 (2012): 130–59.
enjoying the great outdoors: Niels G. Waller, David T. Lykken, and Auke Tellegen, “Occupational Interests, Leisure Time Interests, and Personality: Three Domains or One? Findings from the Minnesota Twin Registry.” In Assessing Individual Differences in Human Behavior: New Concepts, Methods, and Findings, ed. David John Lubinski and René V. Dawis (Palo Alto, CA: Davies-Black Publishing, 1995): 233–59.
having a sweet tooth: Fiona M. Breen, Robert Plomin, and Jane Wardle, “Heritability of Food Preferences in Young Children,” Physiology & Behavior 88 (2006): 443–47.
end up a chain-smoker: Gary E. Swan et al., “Smoking and Alcohol Consumption in Adult Male Twins: Genetic Heritability and Shared Environmental Influences,” Journal of Substance Abuse 2 (1990): 39–50.
getting skin cancer: Paul Lichtenstein et al. “Environmental and Heritable Factors in the Causation of Cancer—Analyses of Cohorts of Twins from Sweden, Denmark, and Finland,” New England Journal of Medicine 343 (2000): 78–85.
carry a tune: Elizabeth Theusch and Jane Gitschier, “Absolute Pitch Twin Study and Segregation Analysis,” Twin Research and Human Genetics 14 (2011): 173–78.
dunk a basketball: Lisa M. Guth and Stephen M. Roth, “Genetic Influence and Athletic Performance,” Current Opinion in Pediatrics 25 (2013): 653–58.
solve a quadratic equation: Bonamy Oliver et al., “A Twin Study of Teacher-Reported Mathematics Performance and Low Performance in 7-Year-Olds,” Journal of Educational Psychology 96 (2004): 504–17.
“I could only swim breaststroke”: Chambliss, interview.
“I had horribly bad coaches”: Chambliss, interview. The tremendous importance of teacher quality to trajectories of academic achievement is documented in Eric A. Hanushek, “Valuing Teachers: How Much Is a Good Teacher Worth?” Education Next 11 (2011), 40–45.
researchers in London: Personal communication with Robert Plomin, June 21, 2015. For a review of heritability of personality traits, see Turkheimer, Pettersson, and Horn, “Phenotypic Null Hypothesis.” It’s worth noting that there are behavioral genetics studies that do not rely on twins, and also that heritability is a topic too complex to fully summarize here. In particular, there are interactions between different genes, between genes and the environment, and epigenetic effects. Relatedly, there is an ongoing debate as to the proportion of environmental influence that can be attributed to parenting. Definitively teasing apart the effects of parenting from genetic heritage is difficult. Chiefly, this is because you can’t randomly swap human children to live with different parents. However, you can do exactly that with rat pups and their moms. You can, for example, randomly assign rat pups to grow up with very nurturing mothers or very negligent ones. Neurobiologist Michael Meaney has done exactly that, and he has found that nurturing rats—who lick and groom and nurse their pups more than average—raise pups who are less stressed when dealing with challenging situations. The effects last into adulthood, and in fact, rat pups who are born to low-lick moms but, within twenty-four hours of birth, are switched to be raised by high-lick moms, grow up to be high-lick moms themselves. See Darlene Francis, Josie Diorio, Dong Liu, and Michael J. Meaney, “Nongenomic Transmission Across Generations of Maternal Behavior and Stress Responses in the Rat,” Science 286 (1999): 1155–58.
traits are polygenic: Christopher F. Chabris et al., “The Fourth Law of Behavioral Genetics,” Current Directions in Psychological Science 24 (2015): 304–12.
at least 697 different genes: Andrew R. Wood et al., “Defining the Role of Common Variation in the Genomic and Biological Architecture of Adult Human Height,” Nature Genetics 46 (2014): 1173–86.
as many as twenty-five thousand different genes: “A Brief Guide to Genomics,” National Human Genome Research Institute, last modified August 27, 2015, http://www.genome.gov/18016863.
Wechsler Adult Intelligence Scale: The Wechsler tests are now published by Pearson’s Clinical Assessment.