Atomic Habits Endnotes
On this page, I have included a detailed list of notes, references, and citations for each chapter in Atomic Habits. I trust that most readers will find this list to be sufficient. However, I also realize that scientific literature changes over time and the references for this book may need to be updated.
Furthermore, I fully expect that I have made a mistake somewhere—either in attributing an idea to the wrong person or not giving credit to someone where it is due. If you believe I have made an error, please email me at [email protected] so I can fix the issue as soon as possible. While the notes and citations in the printed version of the book are fixed, I will continue to update this page as new information becomes available.
7 We all deal with setbacks: What about luck, you might ask? Luck matters, certainly. Habits are not the only thing that influence your success, but they are probably the most important factor that is within your control. And the only self‐improvement strategy that makes any sense is to focus on what you can control.
8 The entrepreneur and investor Naval Ravikant: Naval Ravikant (@naval), “To write a great book, you must first become the book,” Twitter, May 15, 2018, https://twitter.com/naval/status/996460948029362176.
9 “stimulus, response, reward”: B. F. Skinner, The Behavior of Organisms (New York: Appleton‐Century‐Crofts, 1938).
9 “cue, routine, reward”: Charles Duhigg, The Power of Habit: Why We Do What We Do in Life and Business (New York: Random House, 2014).
13 just a single gold medal at the Olympic Games: Matt Slater, “How GB Cycling Went from Tragic to Magic,” BBC Sport, April 14, 2008, http://news.bbc.co.uk/sport2/hi/olympics/cycling/7534073.stm.
13 the Tour de France: Tom Fordyce, “Tour de France 2017: Is Chris Froome Britain’s Least Loved Great Sportsman?” BBC Sport, July 23, 2017, https://www.bbc.com/sport/cycling/40692045.
13 one of the top bike manufacturers in Europe refused to sell bikes: Richard Moore, Mastermind: How Dave Brailsford Reinvented the Wheel (Glasgow: BackPage Press, 2013).
13 “The whole principle came from the idea”: Matt Slater, “Olympics Cycling: Marginal Gains Underpin Team GB Dominance,” BBC, August 8, 2012, https://www.bbc.com/sport/olympics/19174302.
14 Brailsford and his coaches began by making small adjustments: Tim Harford, “Marginal Gains Matter but Gamechangers Transform,” Tim Harford, April 2017, http://timharford.com/2017/04/marginal‐gains‐matter‐but‐gamechangers‐transform.
14 they even painted the inside of the team truck white: Eben Harrell, “How 1% Performance Improvements Led to Olympic Gold,” Harvard Business Review, October 30, 2015, https://hbr.org/2015/10/how‐1‐performance‐improvements‐led‐to‐olympic‐gold; Kevin Clark, “How a Cycling Team Turned the Falcons Into NFC Champions,” The Ringer, September 12, 2017, https://www.theringer.com/nfl/2017/9/12/16293216/atlanta‐falcons‐thomas‐dimitroff‐cycling‐team‐sky.
14 Just five years after Brailsford took over: Technically, the British riders won 57 percent of the road and track cycling medals at the 2008 Olympics. Fourteen gold medals were available in road and track cycling events. The Brits won eight of them.
14 the Brits raised the bar: “World and Olympic Records Set at the 2012 Summer Olympics,” Wikipedia, December 8, 2017, https://en.wikipedia.org/wiki/World_and_Olympic_records_set_at_the_2012_Summer_Olympics#Cycling.
14 Bradley Wiggins became the first British cyclist: Andrew Longmore, “Bradley Wiggins,” Encyclopaedia Britannica, https://www.britannica.com/biography/Bradley‐Wiggins, last modified April 21, 2018.
14 Chris Froome won: Karen Sparks, “Chris Froome,” Encyclopaedia Britannica, https://www.britannica.com/biography/Chris‐Froome, last modified October 23, 2017.
15 During the ten-year span from 2007 to 2017: “Medals won by the Great Britain Cycling Team at world championships, Olympic Games and Paralympic Games since 2000,” British Cycling, https://www.britishcycling.org.uk/gbcyclingteam/article/Gbrst_gb‐cyclingteam‐GB‐Cycling‐Team‐Medal‐History—0?c=EN#K0dWAPjq84CV8Wzw.99, accessed June 8, 2018.
15 you’ll end up thirty-seven times better: Jason Shen, an entrepreneur and writer, received an early look at this book. After reading this chapter, he remarked: “If the gains were linear, you’d predict to be 3.65x better off. But because it is exponential, the improvement is actually 10x greater.” April 3, 2018.
16 Habits are the compound interest: Many people have noted how habits multiply over time. Here are some of my favorite articles and books on the subject: Leo Babauta, “The Power of Habit Investments,” Zen Habits, January 28, 2013, https://zenhabits.net/bank; Morgan Housel, “The Freakishly Strong Base,” Collaborative Fund, October 31, 2017, http://www.collaborativefund.com/blog/the‐freakishly‐strong‐base; Darren Hardy, The Compound Effect (New York: Vanguard Press, 2012).
18 Accomplishing one extra task: As Sam Altman says, “A small productivity gain, compounded over 50 years, is worth a lot.” “Productivity,” Sam Altman. April 10, 2018, http://blog.samaltman.com/productivity.
18 The more tasks you can handle without thinking: Michael (@mmay3r), “The foundation of productivity is habits. The more you do automatically, the more you’re subsequently freed to do. This effect compounds,” Twitter, April 10, 2018, https://twitter.com/mmay3r/status/983837519274889216.
18 each book you read not only teaches: This idea—that learning new ideas increases the value of your old ideas—is something I first heard about from Patrick O’Shaughnessy, who writes, “This is why knowledge compounds. Old stuff that was a 4/10 in value can become a 10/10, unlocked by another book in the future.” http://investorfieldguide.com/reading‐tweet‐storm.
19 Habits are a double-edged sword: I’d like to credit Jason Hreha with originally describing habits to me in this way. Jason Hreha (@jhreha), “They’re a double edged sword,” Twitter, February 21, 2018, https://twitter.com/jhreha/status/966430907371433984.
20 Cancer spends 80 percent of its life undetectable: “How to Live a Longer, Higher Quality Life, with Peter Attia, M.D.,” Investor’s Field Guide, March 7, 2017, http://investorfieldguide.com/attia.
21 The San Antonio Spurs: Matt Moore, “NBA Finals: A Rock, Hammer and Cracking of Spurs’ Majesty in Game 7,” CBS Sports, June 21, 2013, https://www.cbssports.com/nba/news/nba‐finals‐a‐rock‐hammer‐and‐cracking‐of‐spurs‐majesty-in‐game‐7.
22 Inspiration for this drawing came from a tweet titled “Deception of linear vs exponential” by @MlichaelW. May 19, 2018. https://twitter.com/MlichaelW/status/997878086132817920.
22 The seed of every habit: This paragraph was inspired by a quote from Mr. Mircea, an account on Twitter, who wrote, “each habit began its life as a single decision.” https://twitter.com/mistermircea.
25 the goal cannot be what differentiates the winners from the losers: Hat tip to CrossFit coach Ben Bergeron for inspiring this quote during a conversation I had with him on February 28, 2017.
27 You fall to the level of your systems: This line was inspired by the following quote from Archilochus: “We don’t rise to the level of our expectations, we fall to the level of our training.”
30 You can imagine them like the layers of an onion: Hat tip to Simon Sinek. His “Golden Circle” framework is similar in design, but discusses different topics. For more, see Simon Sinek, Start with Why: How Great Leaders Inspire Everyone to Take Action (London: Portfolio/Penguin, 2013), 37.
33 I resolved to stop chewing my nails: The quotes used in this section are presented as a conversation for reading clarity, but were originally written by Clark. See: Brian Clark, “The Powerful Psychological Boost that Helps You Make and Break Habits,” Further, November 14, 2017, https://further.net/pride‐habits.
34 Research has shown that once a person: Christopher J. Bryan et al., “Motivating Voter Turnout by Invoking the Self,” Proceedings of the National Academy of Sciences 108, no. 31 (2011): 12653–12656.
35 There is internal pressure: Leon Festinger, A Theory of Cognitive Dissonance (Stanford, CA: Stanford University Press, 1957).
37 Your identity is literally your “repeated beingness”: Technically, identidem is a word belonging to the Late Latin language. Also, thanks to Tamar Shippony, a reader of jamesclear-com-staging.uar9g7bv-liquidwebsites.com, who originally told me about the etymology of the word identity, which she looked up in the American Heritage Dictionary.
38 We change bit by bit: This is another reason atomic habits are such an effective form of change. If you change your identity too quickly and become someone radically different overnight, then you feel as if you lose your sense of self. But if you update and expand your identity gradually, you will find yourself reborn into someone totally new and yet still familiar. Slowly—habit by habit, vote by vote—you become accustomed to your new identity. Atomic habits and gradual improvement are the keys to identity change without identity loss.
43 Edward Thorndike conducted an experiment: Peter Gray, Psychology, 6th ed. (New York: Worth, 2011), 108–109.
43 “by some simple act, such as pulling at a loop of cord”: Edward L. Thorndike, “Animal Intelligence: An Experimental Study of the Associative Processes in Animals,” Psychological Review: Monograph Supplements 2, no. 4 (1898), doi:10.1037/h0092987.
44 “behaviors followed by satisfying consequences”: This is an abbreviated version of the original quote from Thorndike, which reads: “responses that produce a satisfying effect in a particular situation become more likely to occur again in that situation, and responses that produce a discomforting effect become less likely to occur again in that situation.” For more, see Peter Gray, Psychology, 6th ed. (New York: Worth, 2011), 108–109.
45 Neurological activity in the brain is high: Charles Duhigg, The Power of Habit: Why We Do What We Do in Life and Business (New York: Random House, 2014), 15; Ann M. Graybiel, “Network‐Level Neuroplasticity in Cortico‐Basal Ganglia Pathways,” Parkinsonism and Related Disorders 10, no. 5 (2004), doi:10.1016/j.parkreldis.2004.03.007.
45 “Habits are, simply, reliable solutions”: Jason Hreha, “Why Our Conscious Minds Are Suckers for Novelty,” Revue, https://www.getrevue.co/profile/jason/issues/why‐our‐conscious‐minds‐are‐suckers‐for‐novelty‐54131, accessed June 8, 2018.
45 As habits are created: John R. Anderson, “Acquisition of Cognitive Skill,” Psychological Review 89, no. 4 (1982), doi:10.1037/0033–295X.89.4.369.
46 the brain remembers the past: Shahram Heshmat, “Why Do We Remember Certain Things, But Forget Others,” Psychology Today, October 8, 2015, https://www.psychologytoday.com/us/blog/science‐choice/201510/why‐do‐we-remember‐certain‐things‐forget‐others.
46 the conscious mind is the bottleneck: William H. Gladstones, Michael A. Regan, and Robert B. Lee, “Division of Attention: The Single‐Channel Hypothesis Revisited,” Quarterly Journal of Experimental Psychology Section A 41, no. 1 (1989), doi:10.1080/14640748908402350.
46 the conscious mind likes to pawn off tasks: Daniel Kahneman, Thinking, Fast and Slow (New York: Farrar, Straus and Giroux, 2015).
46 Habits reduce cognitive load: John R. Anderson, “Acquisition of Cognitive Skill,” Psychological Review 89, no. 4 (1982), doi:10.1037/0033–295X.89.4.369.
49 Feelings of pleasure and disappointment: Antonio R. Damasio, The Strange Order of Things: Life, Feeling, and the Making of Cultures (New York: Pantheon Books, 2018); Lisa Feldman Barrett, How Emotions Are Made (London: Pan Books, 2018).
59 The psychologist Gary Klein: I originally heard about this story from Daniel Kahneman, but it was confirmed by Gary Klein in an email on March 30, 2017. Klein also covers the story in his own book, which uses slightly different quotes: Gary A. Klein, Sources of Power: How People Make Decisions (Cambridge, MA: MIT Press, 1998), 43–44.
60 military analysts can identify which blip on a radar screen: Gary A. Klein, Sources of Power: How People Make Decisions (Cambridge, MA: MIT Press, 1998), 38–40.
60 Museum curators have been known to discern: The story of the Getty kouros, covered in Malcolm Gladwell’s book Blink, is a famous example. The sculpture, initially believed to be from ancient Greece, was purchased for $10 million. The controversy surrounding the sculpture happened later when one expert identified it as a forgery upon first glance.
60 Experienced radiologists can look at a brain scan: Siddhartha Mukherjee, “The Algorithm Will See You Now,” New Yorker, April 3, 2017, https://www.newyorker.com/magazine/2017/04/03/ai‐versus‐md.
60 The human brain is a prediction machine: The German physician Hermann von Helmholtz developed the idea of the brain being a “prediction machine.”
62 the clerk swiped the customer’s actual credit card: Helix van Boron, “What’s the Dumbest Thing You’ve Done While Your Brain Is on Autopilot,” Reddit, August 21, 2017,
62 she kept asking coworkers if they had washed their hands: SwordOfTheLlama, “What Strange Habits Have You Picked Up from Your Line of Work,” Reddit, January 4, 2016, https://www.reddit.com/r/AskReddit/comments/3zckq6/what_strange_habits_have_you_picked_up_from_your/cyl3nta.
62 story of a man who had spent years working as a lifeguard: SwearImaChick, “What Strange Habits Have You Picked Up from Your Line of Work,” Reddit, January 4, 2016, https://www.reddit.com/r/AskReddit/comments/3zckq6/what_strange_habits_have_you_picked_up_from_your/cyl681q.
62 “Until you make the unconscious conscious”: Although this quote by Jung is popular, I had trouble tracking down the original source. It’s probably a paraphrase of this passage: “The psychological rule says that when an inner situation is not made conscious, it happens outside, as fate. That is to say, when the individual remains undivided and does not become conscious of his inner opposite, the world must perforce act out the conflict and be torn into opposing halves.” For more, see C. G. Jung, Aion: Researches into the Phenomenology of the Self (Princeton, NJ: Princeton University Press, 1959), 71.
63 Pointing-and-Calling reduces errors: Alice Gordenker, “JR Gestures,” Japan Times, October 21, 2008, https://www.japantimes.co.jp/news/2008/10/21/reference/jr‐gestures/#.WvIG49Mvzu1.
63 The MTA subway system in New York City: Allan Richarz, “Why Japan’s Rail Workers Can’t Stop Pointing at Things,” Atlas Obscura, March 29, 2017, https://www.atlasobscura.com/articles/pointing‐and‐calling‐japan‐trains.
69 researchers in Great Britain began working: Sarah Milne, Sheina Orbell, and Paschal Sheeran, “Combining Motivational and Volitional Interventions to Promote Exercise Participation: Protection Motivation Theory and Implementation Intentions,” British Journal of Health Psychology 7 (May 2002): 163–184.
70 implementation intentions are effective: Peter Gollwitzer and Paschal Sheeran, “Implementation Intentions and Goal Achievement: A Meta‐Analysis of Effects and Processes,” Advances in Experimental Social Psychology 38 (2006): 69–119.
70 writing down the exact time and date of when you will get a flu shot: Katherine L. Milkman, John Beshears, James J. Choi, David Laibson, and Brigitte C. Madrian, “Using Implementation Intentions Prompts to Enhance Influenza Vaccination Rates,” Proceedings of the National Academy of Sciences 108, no. 26 (June 2011): 10415–10420.
70 recording the time of your colonoscopy appointment: Katherine L. Milkman, John Beshears, James J. Choi, David Laibson, and Brigitte C. Madrian, “Planning Prompts as a Means of Increasing Preventive Screening Rates,” Preventive Medicine 56, no. 1 (January 2013): 92–93.
70 voter turnout increases: David W. Nickerson and Todd Rogers, “Do You Have a Voting Plan? Implementation Intentions, Voter Turnout, and Organic Plan Making,” Psychological Science 21, no. 2 (2010): 194–199.
70 Other successful government programs: “Policymakers around the World Are Embracing Behavioural Science,” The Economist, May 18, 2017, https://www.economist.com/news/international/21722163‐experimental‐iterative‐data‐driven‐approach‐gaining‐ground‐policymakers‐around.
70 people who make a specific plan for when and where: Edwin Locke and Gary Latham, “Building a Practically Useful Theory of Goal Setting and Task Motivation: A 35‐Year Odyssey,” American Psychologist 57, no. 9 (2002): 705–717, doi:10.1037//0003–066x.57.9.705.
72 hope is usually higher: Hengchen Dai, Katherine L. Milkman, and Jason Riis, “The Fresh Start Effect: Temporal Landmarks Motivate Aspirational Behavior,” PsycEXTRA Dataset, 2014, doi:10.1037/e513702014–058.
72 writer Jason Zweig noted: Jason Zweig, “Elevate Your Financial IQ: A Value Packed Discussion with Jason Zweig,” interview by Shane Parrish, The Knowledge Project, Farnam Street, audio, https://www.fs.blog/2015/10/jason‐zweig-knowledge‐project.
72 many ways to use implementation intentions: For the term habit stacking, I am indebted to S. J. Scott, who wrote a book by the same name. From what I understand, his concept is slightly different, but I like the term and thought it appropriate to use in this chapter. Previous writers such as Courtney Carver and Julien Smith have also used the term habit stacking, but in different contexts.
72 The French philosopher Denis Diderot: “Denis Diderot,” New World Encyclopedia, http://www.newworldencyclopedia.org/entry/Denis_Diderot, last modified October 26, 2017.
73 acquired a scarlet robe: Encyclopædia Britannica, vol. 8 (1911), s.v. “Denis Diderot.” Diderot’s scarlet robe is frequently described as a gift from a friend. However, I could find no original source claiming it was a gift nor any mention of the friend who supplied the robe. If you happen to know any historians specializing in robe acquisitions, feel free to point them my way so we can clarify the mystery of the source of Diderot’s famous scarlet robe.
73 “no more coordination, no more unity, no more beauty”: Denis Diderot, “Regrets for My Old Dressing Gown,” trans. Mitchell Abidor, 2005, https://www.marxists.org/reference/archive/diderot/1769/regrets.htm.
73 The Diderot Effect states: Juliet Schor, The Overspent American: Why We Want What We Don’t Need (New York: HarperPerennial, 1999).
74 which was created by BJ Fogg: In this chapter, I used the term habit stacking to refer to linking a new habit to an old one. For this idea, I give credit to BJ Fogg. In his work, Fogg uses the term anchoring to describe this approach because your old habit acts as an “anchor” that keeps the new one in place. No matter what term you prefer, I believe it is a very effective strategy. You can learn more about Fogg’s work and his Tiny Habits Method at https://www.tinyhabits.com.
77 “One in, one out”: Dev Basu (@devbasu), “Have a one‐in‐one‐out policy when buying things,” Twitter, February 11, 2018, https://twitter.com/devbasu/status/962778141965000704.
81 Anne Thorndike: Anne N. Thorndike et al., “A 2‐Phase Labeling and Choice Architecture Intervention to Improve Healthy Food and Beverage Choices,” American Journal of Public Health 102, no. 3 (2012), doi:10.2105/ajph.2011.300391.
82 choose products not because of what they are: Multiple research studies have shown that the mere sight of food can make us feel hungry even when we don’t have actual physiological hunger. According to one researcher, “dietary behaviors are, in large part, the consequence of automatic responses to contextual food cues.” For more, see D. A. Cohen and S. H. Babey, “Contextual Influences on Eating Behaviours: Heuristic Processing and Dietary Choices,” Obesity Reviews 13, no. 9 (2012), doi:10.1111/j.1467–789x.2012.01001.x; and Andrew J. Hill, Lynn D. Magson, and John E. Blundell, “Hunger and Palatability: Tracking Ratings of Subjective Experience Before, during and after the Consumption of Preferred and Less Preferred Food,” Appetite 5, no. 4 (1984), doi:10.1016/s0195– 6663(84)80008–2.
83 Behavior is a function of their Person in the Environment: Kurt Lewin, Principles of Topological Psychology (New York: McGraw‐Hill, 1936).
83 Suggestion Impulse Buying: Hawkins Stern, “The Significance of Impulse Buying Today,” Journal of Marketing 26, no. 2 (1962), doi:10.2307/1248439.
83 45 percent of Coca-Cola sales: Michael Moss, “Nudged to the Produce Aisle by a Look in the Mirror,” New York Times, August 27, 2013, https://www.nytimes.com/2013/08/28/dining/wooing‐us‐down‐the‐produce‐aisle.html?_r=0.
83 People drink Bud Light because: The more exposure people have to food, the more likely they are to purchase it and eat it. T. Burgoine et al., “Associations between Exposure to Takeaway Food Outlets, Takeaway Food Consumption, and Body Weight in Cambridgeshire, UK: Population Based, Cross Sectional Study,” British Medical Journal 348, no. 5 (2014), doi:10.1136/bmj.g1464.
84 The human body has about eleven million sensory receptors: Timothy D. Wilson, Strangers to Ourselves: Discovering the Adaptive Unconscious (Cambridge, MA: Belknap Press, 2004), 24.
84 half of the brain’s resources are used on vision: B. R. Sheth et al., “Orientation Maps of Subjective Contours in Visual Cortex,” Science 274, no. 5295 (1996), doi:10.1126/science.274.5295.2110.
85 When their energy use was obvious and easy to track: This story was told to Donella Meadows at a conference in Kollekolle, Denmark, in 1973. For more, see Donella Meadows and Diana Wright, Thinking in Systems: A Primer (White River Junction, VT: Chelsea Green, 2015), 109.
85 the stickers cut bathroom cleaning costs: The actual estimate was 8 percent, but given the variables used, anywhere between 5 percent and 10 percent savings annually is a reasonable guess. Blake Evans‐Pritchard, “Aiming to Reduce Cleaning Costs,” Works That Work, Winter 2013, https://worksthatwork.com/1/urinal‐fly.
88 sleeping . . . was the only action that happened in that room: “Techniques involving stimulus control have even been successfully used to help people with insomnia. In short, those who had trouble falling asleep were told to only go to their room and lie in their bed when they were tired. If they couldn’t fall asleep, they were told to get up and change rooms. Strange advice, but over time, researchers found that by associating the bed with ‘It’s time to go to sleep’ and not with other activities (reading a book, just lying there, etc.), participants were eventually able to quickly fall asleep due to the repeated process: it became almost automatic to fall asleep in their bed because a successful trigger had been created.” For more, see Charles M. Morin et al., “Psychological and Behavioral Treatment of Insomnia: Update of the Recent Evidence (1998–2004),” Sleep 29, no. 11 (2006), doi:10.1093/sleep/29.11.1398; and Gregory Ciotti, “The Best Way to Change Your Habits? Control Your Environment,” Sparring Mind, https://www.sparringmind.com/changing‐habits.
88 habits can be easier to change in a new environment: S. Thompson, J. Michaelson, S. Abdallah, V. Johnson, D. Morris, K. Riley, and A. Simms, ‘Moments of Change’ as Opportunities for Influencing Behaviour: A Report to the Department for Environment, Food and Rural Affairs (London: Defra, 2011),
88 when you step outside your normal environment: Various research studies have found that it is easier to change your behavior when your environment changes. For example, students change their television watching habits when they transfer schools. Wendy Wood and David T. Neal, “Healthy through Habit: Interventions for Initiating and Maintaining Health Behavior Change,” Behavioral Science and Policy 2, no. 1 (2016), doi:10.1353/bsp.2016.0008; W. Wood, L. Tam, and M. G. Witt, “Changing Circumstances, Disrupting Habits,” Journal of Personality and Social Psychology 88, no. 6 (2005), doi:10.1037/0022–35188.8.131.528
88 You aren’t battling old environmental cues: Perhaps this is why 36 percent of successful changes in behavior were associated with a move to a new place. Melissa Guerrero‐Witt, Wendy Wood, and Leona Tam, “Changing Circumstances, Disrupting Habits,” PsycEXTRA Dataset 88, no. 6 (2005), doi:10.1037/e529412014–144.
91 Follow-up research revealed that 35 percent of service members: Lee N. Robins et al., “Vietnam Veterans Three Years after Vietnam: How Our Study Changed Our View of Heroin,” American Journal on Addictions 19, no. 3 (2010), doi:10.1111/j.1521–0391.2010.00046.x.
91 the creation of the Special Action Office of Drug Abuse Prevention: “Excerpts from President’s Message on Drug Abuse Control,” New York Times, June 18, 1971, https://www.nytimes.com/1971/06/18/archives/excerpts‐from‐presidents‐message‐on‐drug‐abuse‐control.html.
91 nine out of ten soldiers who used heroin in Vietnam: Lee N. Robins, Darlene H. Davis, and David N. Nurco, “How Permanent Was Vietnam Drug Addiction?” American Journal of Public Health 64, no. 12 (suppl.) (1974), doi:10.2105/ajph.64.12_suppl.38.
92 90 percent of heroin users become re-addicted: Bobby P. Smyth et al., “Lapse and Relapse following Inpatient Treatment of Opiate Dependence,” Irish Medical Journal 103, no. 6 (June 2010).
92 “disciplined” people are better at structuring their lives: Wilhelm Hofmann et al., “Everyday Temptations: An Experience Sampling Study on How People Control Their Desires,” PsycEXTRA Dataset 102, no. 6 (2012), doi:10.1037/e634112013–146.
93 It’s easier to practice self-restraint when you don’t have to use it: “Our prototypical model of self‐control is angel on one side and devil on the other, and they battle it out. . . . We tend to think of people with strong willpower as people who are able to fight this battle effectively. Actually, the people who are really good at self‐control never have these battles in the first place.” For more, see Brian Resnick, “The Myth of Self‐Control,” Vox, November 24, 2016, https://www.vox.com/science‐and‐health/2016/11/3/13486940/self‐control‐psychology‐myth.
93 A habit that has been encoded in the mind is ready to be used: Wendy Wood and Dennis Rünger, “Psychology of Habit,” Annual Review of Psychology 67, no. 1 (2016), doi:10.1146/annurev‐psych‐122414–033417.
93 The cues were still internalized: “The Biology of Motivation and Habits: Why We Drop the Ball,” Therapist Uncensored, 20:00, http://www.therapistuncensored.com/biology‐of‐motivation‐habits, accessed June 8, 2018.
93 Shaming obese people with weight-loss presentations: Sarah E. Jackson, Rebecca J. Beeken, and Jane Wardle, “Perceived Weight Discrimination and Changes in Weight, Waist Circumference, and Weight Status,” Obesity, 2014, doi:10.1002/oby.20891.
93 Showing pictures of blackened lungs to smokers: Kelly McGonigal, The Upside of Stress: Why Stress Is Good for You, and How to Get Good at It (New York: Avery, 2016), xv.
94 showing addicts a picture of cocaine for just thirty-three milliseconds: Fran Smith, “How Science Is Unlocking the Secrets of Addiction,” National Geographic, September 2017, https://www.nationalgeographic.com/magazine/2017/09/the-addicted‐brain.
101 Niko Tinbergen performed a series of experiments: Nikolaas Tinbergen, The Herring Gull’s World (London: Collins, 1953); “Nikolaas Tinbergen,” New World Encyclopedia, http://www.newworldencyclopedia.org/entry/Nikolaas_Tinbergen, last modified September 30, 2016.
102 the goose will pull any nearby round object: James L. Gould, Ethology: The Mechanisms and Evolution of Behavior (New York: Norton, 1982), 36–41.
103 the modern food industry relies on stretching: Steven Witherly, Why Humans Like Junk Food (New York: IUniverse, 2007).
103 Nearly every food in a bag: “Tweaking Tastes and Creating Cravings,” 60 Minutes, November 27, 2011. https://www.youtube.com/watch?v=a7Wh3uq1yTc.
103 French fries . . . are a potent combination: Steven Witherly, Why Humans Like Junk Food (New York: IUniverse, 2007).
103 such strategies enable food scientists to find the “bliss point”: Michael Moss, Salt, Sugar, Fat: How the Food Giants Hooked Us (London: Allen, 2014).
103 “We’ve gotten too good at pushing our own buttons”: This quote originally appeared in Stephan Guyenet, “Why Are Some People ‘Carboholics’?” July 26, 2017, http://www.stephanguyenet.com/why‐are‐some‐people‐carboholics. The adapted version is given with permission granted in an email exchange with Guyenet in April 2018.
105 The importance of dopamine: “The importance of dopamine was discovered by accident. In 1954, James Olds and Peter Milner, two neuroscientists at McGill University, decided to implant an electrode deep into the center of a rat’s brain. The precise placement of the electrode was largely happenstance; at the time, the geography of the mind remained a mystery. But Olds and Milner got lucky. They inserted the needle right next to the nucleus accumbens (NAcc), a part of the brain that generates pleasurable feelings. Whenever you eat a piece of chocolate cake, or listen to a favorite pop song, or watch your favorite team win the World Series, it is your NAcc that helps you feel so happy. But Olds and Milner quickly discovered that too much pleasure can be fatal. They placed the electrodes in several rodents’ brains and then ran a small current into each wire, making the NAccs continually excited. The scientists noticed that the rodents lost interest in everything. They stopped eating and drinking. All courtship behavior ceased. The rats would just huddle in the corners of their cages, transfixed by their bliss. Within days, all of the animals had perished. They died of thirst. For more, see Jonah Lehrer, How We Decide (Boston: Houghton Mifflin Harcourt, 2009).
105 neurological processes behind craving and desire: James Olds and Peter Milner, “Positive Reinforcement Produced by Electrical Stimulation of Septal Area and Other Regions of Rat Brain,” Journal of Comparative and Physiological Psychology 47, no. 6 (1954), doi:10.1037/h0058775.
105 rats lost all will to live: Qun‐Yong Zhou and Richard D. Palmiter, “Dopamine‐Deficient Mice Are Severely Hypoactive, Adipsic, and Aphagic,” Cell 83, no. 7 (1995), doi:10.1016/0092–8674(95)90145–0.
105 without desire, action stopped: Kent C. Berridge, Isabel L. Venier, and Terry E. Robinson, “Taste Reactivity Analysis of 6‐Hydroxydopamine‐Induced Aphagia: Implications for Arousal and Anhedonia Hypotheses of Dopamine Function,” Behavioral Neuroscience 103, no. 1 (1989), doi:10.1037//0735–7044.103.1.36.
106 the mice developed a craving so strong: Ross A. Mcdevitt et al., “Serotonergic versus Nonserotonergic Dorsal Raphe Projection Neurons: Differential Participation in Reward Circuitry,” Cell Reports 8, no. 6 (2014), doi:10.1016/j.cel‐rep.2014.08.037.
106 the average slot machine player: Natasha Dow Schüll, Addiction by Design: Machine Gambling in Las Vegas (Princeton, NJ: Princeton University Press, 2014), 55.
106 Habits are a dopamine-driven feedback loop: I first heard the term dopamine-driven feedback loop from Chamath Palihapitiya. For more, see “Chamath Palihapitiya, Founder and CEO Social Capital, on Money as an Instrument of Change,” Stanford Graduate School of Business, November 13, 2017, https://www.youtube.com/watch?v=PMotykw0SIk.
106 dopamine . . . plays a central role in many neurological processes: Researchers later discovered that endorphins and opioids were responsible for pleasure responses. For more, see V. S. Chakravarthy, Denny Joseph, and Raju S. Bapi, “What Do the Basal Ganglia Do? A Modeling Perspective,” Biological Cybernetics 103, no. 3 (2010), doi:10.1007/s00422–010–0401‐y.
106 dopamine is released not only when you experience pleasure: Wolfram Schultz, “Neuronal Reward and Decision Signals: From Theories to Data,” Physiological Reviews 95, no. 3 (2015), doi:10.1152/physrev.00023.2014, fig. 8; Fran Smith, “How Science Is Unlocking the Secrets of Addiction,” National Geographic, September 2017, https://www.nationalgeographic.com/magazine/2017/09/the‐addicted‐brain.
106 whenever dopamine rises, so does your motivation: Dopamine compels you to seek, explore, and take action: “Dopamine‐energized, this mesolimbic SEEKING system, arising from the ventral tegmental area (VTA), encourages foraging, exploration, investigation, curiosity, interest and expectancy. Dopamine fires each time the rat (or human) explores its environment. . . . I can look at the animal and tell when I am tickling its SEEKING system because it is exploring and sniffing.” For more, see Karin Badt, “Depressed? Your ‘SEEKING’ System Might Not Be Working: A Conversation with Neuroscientist Jaak Panksepp,” Huffington Post, December 6, 2017, http://www.huffingtonpost.com/karin‐badt/depressed‐your‐seeking‐sy_b_3616967.html.
106 the reward system that is activated in the brain: Wolfram Schultz, “Multiple Reward Signals in the Brain,” Nature Reviews Neuroscience 1, no. 3 (2000), doi:10.1038/35044563.
108 100 percent of the nucleus accumbens is activated during wanting: Kent Berridge, conversation with author, March 8, 2017.
108 Byrne hacked his stationary bike: Hackster Staff, “Netflix and Cycle!,” Hackster, July 12, 2017, https://blog.hackster.io/netflix‐and‐cycle‐1734d0179deb.
108 “eliminating obesity one Netflix binge at a time”: “Cycflix: Exercise Powered Entertainment,” Roboro, July 8, 2017, https://www.youtube.com/watch?v=‐nc0irLB‐iY.
109 “We see Thursday night as a viewership opportunity”: Jeanine Poggi, “Shonda Rhimes Looks Beyond ABC’s Nighttime Soaps,” AdAge, May 16, 2016,
110 “more probable behaviors will reinforce less probable behaviors”: Jon E. Roeckelein, Dictionary of Theories, Laws, and Concepts in Psychology (Westport, CT: Greenwood Press, 1998), 384.
113 “A genius is not born, but is educated and trained”: Harold Lundstrom, “Father of 3 Prodigies Says Chess Genius Can Be Taught,” Deseret News, December 25, 1992,
116 We imitate the habits of three groups: Peter J. Richerson and Robert Boyd, Not by Genes Alone: How Culture Transformed Human Evolution (Chicago: University of Chicago Press, 2006).
117 “a person’s chances of becoming obese increased by 57 percent”: Nicholas A. Christakis and James H. Fowler, “The Spread of Obesity in a Large Social Network over 32 Years,” New England Journal of Medicine 357, no. 4 (2007), doi:10.1056/nejmsa066082. J. A. Stockman, “The Spread of Obesity in a Large Social Network over 32 Years,” Yearbook of Pediatrics 2009 (2009), doi:10.1016/ s0084–3954(08)79134–6.
117 if one person in a relationship lost weight: Amy A. Gorin et al., “Randomized Controlled Trial Examining the Ripple Effect of a Nationally Available Weight Management Program on Untreated Spouses,” Obesity 26, no. 3 (2018), doi:10.1002/oby.22098.
117 Of the ten people in the class, four became astronauts: Mike Massimino, “Finding the Difference Between ‘Improbable’ and ‘Impossible,’” interview by James Altucher, The James Altucher Show, January 2017, https://jamesaltucher.com/2017/01/mike‐massimino‐i‐am‐not‐good‐enough.
117 the higher your best friend’s IQ at age eleven or twelve: Ryan Meldrum, Nicholas Kavish, and Brian Boutwell, “On the Longitudinal Association between Peer and Adolescent Intelligence: Can Our Friends Make Us Smarter?,” PsyArXiv, February 10, 2018, doi:10.17605/OSF.IO/TVJ9Z.
118 Solomon Asch conducted a series of experiments: Harold Steere Guetzkow, Groups, Leadership and Men: Research in Human Relations (Pittsburgh, PA: Carnegie Press, 1951), 177–190.
120 By the end of the experiment, nearly 75 percent of the subjects: Follow‐up studies show that if there was just one actor in the group who disagreed with the group, then the subject was far more likely to state their true belief that the lines were different lengths. When you have an opinion that dissents from the tribe, it is much easier to stand by it if you have an ally. When you need the strength to stand up to the social norm, find a partner. For more, see Solomon E. Asch, “Opinions and Social Pressure,” Scientific American 193, no. 5 (1955), doi:10.1038/scientificamerican1155–31; and William N. Morris and Robert S. Miller, “The Effects of Consensus‐Breaking and Consensus‐Preempting Partners on Reduction of Conformity,” Journal of Experimental Social Psychology 11, no. 3 (1975), doi:10.1016/ s0022–1031(75)80023–0.
Nearly 75 percent of subjects made the incorrect choice at least once. However, considering the total number of responses throughout the experiment, about two thirds were correct. Either way, the point stands: group pressure can significantly alter our ability to make accurate decisions.
120 a chimpanzee learns an effective way: Lydia V. Luncz, Giulia Sirianni, Roger Mundry, and Christophe Boesch. “Costly culture: differences in nut‐cracking efficiency between wild chimpanzee groups.” Animal Behaviour 137 (2018): 63–73.
127 “I wouldn’t say, ‘because I need food to survive'”: I heard a similar example from the Twitter account, simpolism (@simpolism), “Let’s extend this metaphor. If society is a human body, then the state is the brain. Humans are unaware of their motives. If asked ‘why do you eat?’ you might say ‘bc food tastes good’ and not ‘bc I need food to survive.’ What might a state’s food be? (hint: are pills food?),” Twitter, May 7, 2018, https://twitter.com/simpolism/status/993632142700826624.
130 when emotions and feelings are impaired: Antoine Bechara et al., “Insensitivity to Future Consequences following Damage to Human Prefrontal Cortex,” Cognition 50, no. 1–3 (1994), doi:10.1016/0010–0277(94)90018–3.
130 As the neuroscientist Antonio Damasio: “When Emotions Make Better Decisions— Antonio Damasio,” August 11, 2009. https://www.youtube.com/watch?v=1wup_K2WN0I.
131 You don’t “have” to. You “get” to: I am indebted to my college strength and conditioning coach, Mark Watts, who originally shared this simple mindset shift with me.
131 “I’m not confined to my wheelchair”: RedheadBanshee, “What Is Something Someone Said That Forever Changed Your Way of Thinking,” Reddit, October 22, 2014, https://www.reddit.com/r/AskReddit/comments/2jzn0j/what_is_something_someone_said_that_forever/clgm4s2.
131 “It’s time to build endurance and get fast”: WingedAdventurer, “Instead of Thinking ‘Go Run in the Morning,’ Think ‘Go Build Endurance and Get Fast.’ Make Your Habit a Benefit, Not a Task,” Reddit, January 19, 2017, https://www.reddit.com/r/selfimprovement/comments/5ovrqf/instead_of_thinking_go_run_in_the_morning_think/?st=izmz9pks&sh=059312db.
132 “I’m getting an adrenaline rush to help me concentrate”: Alison Wood Brooks, “Get Excited: Reappraising Pre‐Performance Anxiety as Excitement with Minimal Cues,” PsycEXTRA Dataset, June 2014, doi:10.1037/e578192014–321; Caroline Webb, How to Have a Good Day (London: Pan Books, 2017), 238. “Wendy Berry Mendes and Jeremy Jamieson have conducted a number of studies [that] show that people perform better when they decide to interpret their fast heartbeat and breathing as ‘a resource that aids performance.’”
132 Ed Latimore, a boxer and writer: Ed Latimore (@EdLatimore), “Odd realization: My focus and concentration goes up just by putting my headphones [on] while writing. I don’t even have to play any music,” Twitter, May 7, 2018,
142 In the end, they had little to show for their efforts: This story comes from page 29 of Art & Fear by David Bayles and Ted Orland. In an email conversation with Orland on October 18, 2016, he explained the origins of the story. “Yes, the ‘ceramics story’ in ‘Art & Fear’ is indeed true, allowing for some literary license in the retelling. Its real‐world origin was as a gambit employed by photographer Jerry Uelsmann to motivate his Beginning Photography students at the University of Florida. As retold in ‘Art & Fear’ it faithfully captures the scene as Jerry told it to me—except I replaced photography with ceramics as the medium being explored. Admittedly, it would’ve been easier to retain photography as the art medium being discussed, but David Bayles (co‐author) & I are both photographers ourselves, and at the time we were consciously trying to broaden the range of media being referenced in the text. The intriguing thing to me is that it hardly matters what art form was invoked—the moral of the story appears to hold equally true straight across the whole art spectrum (and even outside the arts, for that matter).” Later in that same email, Orland said, “You have our permission to reprint any or all of the ‘ceramics’ passage in your forthcoming book.” In the end, I settled on publishing an adapted version, which combines their telling of the ceramics story with facts from the original source of Uelsmann’s photography students. David Bayles and Ted Orland, Art & Fear: Observations on the Perils (and Rewards) of Artmaking (Santa Cruz, CA: Image Continuum Press, 1993), 29.
142 As Voltaire once wrote: Voltaire, La Bégueule. Conte Moral (1772).
143 long-term potentiation: Long‐term potentiation was discovered by Terje Lømo in 1966. More precisely, he discovered that when a series of signals was repeatedly transmitted by the brain, there was a persistent effect that lasted afterward that made it easier for those signals to be transmitted in the future.
143 “Neurons that fire together wire together”: Donald O. Hebb, The Organization of Behavior: A Neuropsychological Theory (New York: Wiley, 1949).
143 In musicians, the cerebellum: S. Hutchinson, “Cerebellar Volume of Musicians,” Cerebral Cortex 13, no. 9 (2003), doi:10.1093/cercor/13.9.943.
144 Mathematicians, meanwhile, have increased gray matter: A. Verma, “Increased Gray Matter Density in the Parietal Cortex of Mathematicians: A Voxel‐Based Morphometry Study,” Yearbook of Neurology and Neurosurgery 2008 (2008), doi:10.1016/s0513–5117(08)79083–5.
144 When scientists analyzed the brains of taxi drivers in London: Eleanor A. Maguire et al., “Navigation‐Related Structural Change in the Hippocampi of Taxi Drivers,” Proceedings of the National Academy of Sciences 97, no. 8 (2000), doi:10.1073/pnas.070039597; Katherine Woollett and Eleanor A. Maguire, “Acquiring ‘the Knowledge’ of London’s Layout Drives Structural Brain Changes,” Current Biology 21, no. 24 (December 2011), doi:10.1016/j.cub.2011.11.018; Eleanor A. Maguire, Katherine Woollett, and Hugo J. Spiers, “London Taxi Drivers and Bus Drivers: A Structural MRI and Neuropsychological Analysis,” Hippocampus 16, no. 12 (2006), doi:10.1002/hipo.20233.
144 “the actions become so automatic”: George Henry Lewes, The Physiology of Common Life (Leipzig: Tauchnitz, 1860).
144 repetition is a form of change: Apparently, Brian Eno says the same thing in his excellent, creatively inspiring Oblique Strategies card set, which I didn’t know when I wrote this line! Great minds and all that.
145 Automaticity is the ability to perform a behavior: Phillippa Lally et al., “How Are Habits Formed: Modelling Habit Formation in the Real World,” European Journal of Social Psychology 40, no. 6 (2009), doi:10.1002/ejsp.674.
145 habits form based on frequency, not time: Hermann Ebbinghaus was the first person to describe learning curves in his 1885 book Über das Gedächtnis. Hermann Ebbinghaus, Memory: A Contribution to Experimental Psychology (United States: Scholar Select, 2016).
149 this difference in shape played a significant role in the spread of agriculture: Jared Diamond, Guns, Germs, and Steel: The Fates of Human Societies (New York: Norton, 1997).
151 It is human nature to follow the Law of Least Effort: Deepak Chopra uses the phrase “law of least effort” to describe one of his Seven Spiritual Laws of Yoga. This concept is not related to the principle I am discussing here.
153 a garden hose that is bent in the middle: This analogy is a modified version of an idea Josh Waitzkin mentioned in his interview with Tim Ferriss. “The Tim Ferriss Show, Episode 2: Josh Waitzkin,” May 2, 2014, audio, https://soundcloud.com/tim‐ferriss/the‐tim‐ferriss‐show‐episode‐2‐josh‐waitzkin.
154 “it took American workers three times as long to assemble their sets”: James Surowiecki, “Better All the Time,” New Yorker, November 10, 2014, https://www.newyorker.com/magazine/2014/11/10/better‐time.
154 addition by subtraction: Addition by subtraction is an example of a larger principle known as inversion, which I have written about previously at https://james clear.com/inversion. I’m indebted to Shane Parrish for priming my thoughts on this topic by writing about why “avoiding stupidity is easier than seeking brilliance.” Shane Parrish, “Avoiding Stupidity Is Easier Than Seeking Brilliance,” Farnam Street, June 2014, https://www.fs.blog/2014/06/avoiding‐stupidity.
155 those percentage points represent millions in tax revenue: Owain Service et al., “East: Four Simple Ways to Apply Behavioural Insights,” Behavioural Insights Team, 2015, http://38r8om2xjhhl25mw24492dir.wpengine.netdna‐cdn.com/wp‐content/uploads/2015/07/BIT‐Publication‐EAST_FA_WEB.pdf.
156 Nuckols dialed in his cleaning habits: Oswald Nuckols is an alias, used by request.
156 “perfect time to clean the toilet”: Saul_Panzer_NY, “[Question] What One Habit Literally Changed Your Life?” Reddit, June 5, 2017, https://www.reddit.com/r/getdisciplined/comments/6fgqbv/question_what_one_habit_literally_changed_your/diieswq.
159 “arsenal of routines”: Twyla Tharp and Mark Reiter, The Creative Habit: Learn It and Use It for Life: A Practical Guide (New York: Simon and Schuster, 2006).
160 40 to 50 percent of our actions on any given day are done out of habit: Wendy Wood, “Habits Across the Lifespan,” 2006, https://www.researchgate.net/publication/315552294_Habits_Across_the_Lifespan.
160 habits you follow without thinking: Benjamin Gardner, “A Review and Analysis of the Use of ‘Habit’ in Understanding, Predicting and Influencing Health‐Related Behaviour,” Health Psychology Review 9, no. 3 (2014), doi:10.1080/17437199.2013.876238.
160 decisive moments: Shoutout to Henri Cartier‐Bresson, one of the greatest street photographers of all time, who coined the term decisive moment, but for an entirely different purpose: capturing amazing images at just the right time.
162 the Two-Minute Rule: Hat tip to David Allen, whose version of the Two‐Minute Rule states, “If it takes less than two minutes, then do it now.” For more, see David Allen, Getting Things Done (New York: Penguin, 2015).
164 power-down habit: Author Cal Newport uses a shutdown ritual in which he does a last email inbox check, prepares his to‐do list for the next day, and says “shutdown complete” to end work for the day. For more, see Cal Newport, Deep Work (Boston: Little, Brown, 2016).
165 He always stopped journaling before it seemed like a hassle: Greg McKeown, Essentialism: The Disciplined Pursuit of Less (New York: Crown, 2014), 78.
165 habit shaping: Gail B. Peterson, “A Day of Great Illumination: B. F. Skinner’s Discovery of Shaping,” Journal of the Experimental Analysis of Behavior 82, no. 3 (2004), doi:10.1901/jeab.2004.82–317.
169 he remained in his study and wrote furiously: Adèle Hugo and Charles E. Wilbour, Victor Hugo, by a Witness of His Life (New York: Carleton, 1864).
170 A commitment device is a choice you make in the present: Gharad Bryan, Dean Karlan, and Scott Nelson, “Commitment Devices,” Annual Review of Economics 2, no. 1 (2010), doi:10.1146/annurev.economics.102308.124324.
170 outlet timer cuts off the power to router: “Nir Eyal: Addictive Tech, Killing Bad Habits & Apps for Life Hacking—#260,” interview by Dave Asprey, Bulletproof, November 13, 2015, https://blog.bulletproof.com/nir‐eyal‐life‐hacking‐260/.
170 This is also referred to as a “Ulysses pact”: Peter Ubel, “The Ulysses Strategy,” The New Yorker, December 11, 2014, https://www.newyorker.com/business/currency/ulysses‐strategy‐self‐control.
171 Patterson’s business went from losing money to making $5,000 in profit: “John H. Patterson—Ringing Up Success with the Incorruptible Cashier,” Dayton Innovation Legacy, http://www.daytoninnovationlegacy.org/patterson.html, accessed June 8, 2016.
172 onetime actions that lead to better long-term habits: James Clear (@james_clear), “What are one‐time actions that pay off again and again in the future?” Twitter, February 11, 2018, https://twitter.com/james_clear/status/962694722702790659
174 “Civilization advances by extending the number of operations”: Alfred North Whitehead, Introduction to Mathematics (Cambridge, UK: Cambridge University Press, 1911), 166.
175 The average person spends over two hours per day on social media: “GWI Social,” GlobalWebIndex, 2017, Q3, https://cdn2.hubspot.net/hubfs/304927/Downloads/GWI%20Social%20Summary%20Q3%202017.pdf.
183 over nine million people called it home: “Population Size and Growth of Major Cities, 1998 Census,” Population Census Organization, http://www.statpak.gov.pk/depts/pco/statistics/pop_major_cities/pop_major_cities.html.
183 Over 60 percent of Karachi’s residents: Sabiah Askari, Studies on Karachi: Papers Presented at the Karachi Conference 2013 (Newcastle upon Tyne, UK: Cambridge Scholars, 2015).
184 It was this public health crisis that had brought Luby to Pakistan: Atul Gawande, The Checklist Manifesto: How to Get Things Right (Gurgaon, India: Penguin Random House, 2014).
184 “In Pakistan, Safeguard was a premium soap”: All quotes in this section are from an email conversation with Stephen Luby on May 28, 2018.
185 The rate of diarrhea fell by 52 percent: Stephen P. Luby et al., “Effect of Handwashing on Child Health: A Randomised Controlled Trial,” Lancet 366, no. 9481 (2005), doi:10.1016/s0140–6736(05)66912–7.
185 “Over 95 percent of households”: Anna Bowen, Mubina Agboatwalla, Tracy Ayers, Timothy Tobery, Maria Tariq, and Stephen P. Luby. “Sustained improvements in handwashing indicators more than 5 years after a cluster‐randomised, community‐based trial of handwashing promotion in Karachi, Pakistan,” Tropical Medicine & International Health 18, no. 3 (2013): 259–267. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4626884/.
185 Chewing gum had been sold commercially throughout the 1800s: Mary Bellis, “How We Have Bubble Gum Today,” ThoughtCo, October 16, 2017, https://www.thoughtco.com/history‐of‐bubble‐and‐chewing‐gum‐1991856.
185 Wrigley revolutionized the industry: Jennifer P. Mathews, Chicle: The Chewing Gum of the Americas, from the Ancient Maya to William Wrigley (Tucson: University of Arizona Press, 2009), 44–46.
185 Wrigley became the largest chewing gum company: “William Wrigley, Jr.,” Encyclopædia Britannica, https://www.britannica.com/biography/William‐Wrigley‐Jr, accessed June 8, 2018.
186 Toothpaste had a similar trajectory: Charles Duhigg, The Power of Habit: Why We Do What We Do in Life and Business (New York: Random House, 2014), chap. 2.
186 he started avoiding her: Sparkly_alpaca, “What Are the Coolest Psychology Tricks That You Know or Have Used?” Reddit, November 11, 2016, https://www.reddit.com/r/AskReddit/comments/5cgqbj/what_are_the_coolest_psychology_tricks_that_you/d9wcqsr/.
187 The earliest remains of modern humans: Ian Mcdougall, Francis H. Brown, and John G. Fleagle, “Stratigraphic Placement and Age of Modern Humans from Kibish, Ethiopia,” Nature 433, no. 7027 (2005), doi:10.1038/nature03258.
187 the neocortex . . . was roughly the same: Some research indicates that the size of the human brain reached modern proportions around three hundred thousand years ago. Evolution never stops, of course, and the shape of the structure appears to have continued to evolve in meaningful ways until it reached both modern size and shape sometime between one hundred thousand and thirty‐five thousand years ago. Simon Neubauer, Jean‐Jacques Hublin, and Philipp Gunz, “The Evolution of Modern Human Brain Shape,” Science Advances 4, no. 1 (2018): eaao5961.
187 society has shifted to a predominantly delayed-return environment: The original research on this topic used the terms delayed-return societies and immediate-return societies. James Woodburn, “Egalitarian Societies,” Man 17, no. 3 (1982), doi:10.2307/2801707. I first heard of the difference between immediate‐return environments and delayed‐return environments in a lecture from Mark Leary. Mark Leary, Understanding the Mysteries of Human Behavior (Chantilly, VA: Teaching, 2012).
188 The world has changed much in recent years: The rapid environmental changes of recent centuries have far outpaced our biological ability to adapt. On average, it takes about twenty‐five thousand years for meaningful genetic changes to be selected for in a human population. For more, see Edward O. Wilson, Sociobiology (Cambridge, MA: Belknap Press, 1980), 151.
188 our brains evolved to prefer quick payoffs to long-term ones: Daniel Gilbert, “Humans Wired to Respond to Short‐Term Problems,” interview by Neal Conan, Talk of the Nation, NPR, July 3, 2006, https://www.npr.org/templates/story/story.php?storyId=5530483.
188 Disease and infection won’t show up for days or weeks, even years: The topics of irrational behavior and cognitive biases have become quite popular in recent years. However, many actions that seem irrational on the whole have rational origins if you consider their immediate outcome.
189 Frédéric Bastiat: Frédéric Bastiat and W. B. Hodgson, What Is Seen and What Is Not Seen: Or Political Economy in One Lesson (London: Smith, 1859).
189 Future You: Hat tip to behavioral economist Daniel Goldstein, who said, “It’s an unequal battle between the present self and the future self. I mean, let’s face it, the present self is present. It’s in control. It’s in power right now. It has these strong, heroic arms that can lift doughnuts into your mouth. And the future self is not even around. It’s off in the future. It’s weak. It doesn’t even have a lawyer present. There’s nobody to stick up for the future self. And so the present self can trounce all over its dreams.” For more, see Daniel Goldstein, “The Battle between Your Present and Future Self,” TEDSalon NY2011, November 2011, video, https://www.ted.com/talks/daniel_goldstein_the_battle_between_your_present_and_future_self.
190 People who are better at delaying gratification have higher SAT scores: Walter Mischel, Ebbe B. Ebbesen, and Antonette Raskoff Zeiss, “Cognitive and Attentional Mechanisms in Delay of Gratification,” Journal of Personality and Social Psychology 21, no. 2 (1972), doi:10.1037/h0032198; W. Mischel, Y. Shoda, and M. Rodriguez, “Delay of Gratification in Children,” Science 244, no. 4907 (1989), doi:10.1126/science.2658056; Walter Mischel, Yuichi Shoda, and Philip K. Peake, “The Nature of Adolescent Competencies Predicted by Preschool Delay of Gratification,” Journal of Personality and Social Psychology 54, no. 4 (1988), doi:10.1037//0022–35184.108.40.2067; Yuichi Shoda, Walter Mischel, and Philip K. Peake, “Predicting Adolescent Cognitive and Self‐Regulatory Competencies from Preschool Delay of Gratification: Identifying Diagnostic Conditions,” Developmental Psychology 26, no. 6 (1990), doi:10.1037//0012–1649 .26.6.978.
195 “I would start with 120 paper clips in one jar”: Trent Dyrsmid, email to author, April 1, 2015.
196 Benjamin Franklin: Benjamin Franklin and Frank Woodworth Pine, Autobiography of Benjamin Franklin (New York: Holt, 1916), 148.
197 Don’t break the chain of creating every day: Shout‐out to my friend Nathan Barry, who originally inspired me with the mantra, “Create Every Day.”
197 people who track their progress on goals like losing weight: Benjamin Harkin et al., “Does Monitoring Goal Progress Promote Goal Attainment? A Meta‐analysis of the Experimental Evidence,” Psychological Bulletin 142, no. 2 (2016), doi:10.1037/bul0000025.
197 those who kept a daily food log lost twice as much weight as those who did not: Miranda Hitti, “Keeping Food Diary Helps Lose Weight,” WebMD, July 8, 2008, http://www.webmd.com/diet/news/20080708/keeping‐food‐diary‐helps-lose‐weight; Kaiser Permanente, “Keeping a Food Diary Doubles Diet Weight Loss, Study Suggests,” Science Daily, July 8, 2008, https://www.sciencedaily.com/releases/2008/07/080708080738.htm; Jack F. Hollis et al., “Weight Loss during the Intensive Intervention Phase of the Weight‐Loss Maintenance Trial,” American Journal of Preventive Medicine 35, no. 2 (2008), doi:10.1016/j.amepre.2008.04.013; Lora E. Burke, Jing Wang, and Mary Ann Sevick, “Self‐Monitoring in Weight Loss: A Systematic Review of the Literature,” Journal of the American Dietetic Association 111, no. 1 (2011), doi:10.1016/j.jada.2010.10.008.
198 The most effective form of motivation is progress: This line is paraphrased from Greg McKeown, who wrote, “Research has shown that of all forms of human motivation the most effective one is progress.” Greg McKeown, Essentialism: The Disciplined Pursuit of Less (Currency, 2014).
201 The first mistake is never the one that ruins you: In fact, research has shown that missing a habit once has virtually no impact on the odds of developing a habit over the long‐term, regardless of when the mistake occurs. As long as you get back on track, you’re fine. See: Phillippa Lally et al., “How Are Habits Formed: Modelling Habit Formation in the Real World,” European Journal of Social Psychology 40, no. 6 (2009), doi:10.1002/ejsp.674.
201 Missing once is an accident: “Missing once is an accident. Missing twice is the start of a new habit.” I swear I read this line somewhere or perhaps paraphrased it from something similar, but despite my best efforts all of my searches for a source are coming up empty. Maybe I came up with it, but my best guess is it belongs to an unidentified genius instead.
203 “When a measure becomes a target”: This definition of Goodhart’s Law was actually formulated by the British anthropologist Marilyn Strathern. “‘Improving Ratings’: Audit in the British University System,” European Review 5 (1997): 305–321, http://conferences.asucollegeoflaw.com/sciencepublicsphere/files/2014/02/Strathern1997–2.pdf. Goodhart himself reportedly advanced the idea sometime around 1975 and put it formally into writing in 1981. Charles Goodhart, “Problems of Monetary Management: The U.K. Experience,” in Anthony S. Courakis (ed.), Inflation, Depression, and Economic Policy in the West (London: Rowman and Littlefield, 1981), 111–146.
206 “When I suggested this to friends in the Pentagon”: Roger Fisher, “Preventing Nuclear War,” Bulletin of the Atomic Scientists 37, no. 3 (1981), doi:10.1080/ 00963402.1981.11458828.
207 The first seat belt law: Michael Goryl and Michael Cynecki, “Restraint System Usage in the Traffic Population,” Journal of Safety Research 17, no. 2 (1986), doi:10.1016/0022–4375(86)90107–6.
207 wearing a seat belt is enforceable by law: New Hampshire is the lone exception, where seat belts are only required for children. “New Hampshire,” Governors Highway Safety Association,
https://www.ghsa.org/state‐laws/states/new%20hampshire, accessed June 8, 2016.
207 over 88 percent of Americans buckled up: “Seat Belt Use in U.S. Reaches Historic 90 Percent,” National Highway Traffic Safety Administration, November 21, 2016, https://www.nhtsa.gov/press‐releases/seat‐belt‐use‐us‐reaches‐historic‐90‐percent.
208 Bryan Harris: Bryan Harris, email conversation with author, October 24, 2017.
210 She does the “song a day” challenge: Courtney Shea, “Comedian Margaret Cho’s Tips for Success: If You’re Funny, Don’t Do Comedy,” Globe and Mail, July 1, 2013,
210 Thomas Frank, an entrepreneur in Boulder, Colorado: Thomas Frank, “How Buffer Forces Me to Wake Up at 5:55 AM Every Day,” College Info Geek, July 2, 2014, https://collegeinfogeek.com/early‐waking‐with‐buffer/.
217 Phelps has won more Olympic medals: “Michael Phelps Biography,” Biography, https://www.biography.com/people/michael‐phelps‐345192, last modified March 29, 2018.
217 El Guerrouj: Doug Gillan, “El Guerrouj: The Greatest of All Time,” IAFF, November 15, 2004, https://www.iaaf.org/news/news/el‐guerrouj‐the‐greatest‐of‐all‐time.
217 they differ significantly in height: Heights and weights for Michael Phelps and Hicham El Guerrouj were pulled from their athlete profiles during the 2008 Summer Olympics. “Michael Phelps,” ESPN, 2008, http://www.espn.com/olympics/summer08/fanguide/athlete?athlete=29547l; “Hicham El Guerrouj,” ESPN, 2008, http://www.espn.com/oly/summer08/fanguide/athlete?athlete=29886.
217 same length inseam on their pants: David Epstein, The Sports Gene: Inside the Science of Extraordinary Athletic Performance (St. Louis, MO: Turtleback Books, 2014). See also: “Are atletes really getting faster, better, stronger?” by David Epstein.
218 average height of Olympic gold medalists in the men’s 1,500-meter run: Alex Hutchinson, “The Incredible Shrinking Marathoner,” Runner’s World, November 12, 2013, https://www.runnersworld.com/sweat‐science/the‐incredible‐shrinking‐marathoner.
218 average height of Olympic gold medalists in the men’s 100-meter: Alvin Chang, “Want to Win Olympic Gold? Here’s How Tall You Should Be for Archery, Swimming, and More,” Vox, August 9, 2016,
219 “Genes can predispose, but they don’t predetermine”: Gabor Maté, “Dr. Gabor Maté—New Paradigms, Ayahuasca, and Redefining Addiction,” The Tim Ferriss Show, February 20, 2018, https://tim.blog/2018/02/20/gabor‐mate/.
220 Genes have been shown to influence everything: “All traits are heritable” is a bit of an exaggeration, but not by much. Concrete behavioral traits that patently depend on content provided by the home or culture are, of course, not heritable at all; which language you speak, which religion you worship in, which political party you belong to. But behavioral traits that reflect the underlying talents and temperaments are heritable: how proficient with language you are, how religious, how liberal or conservative. General intelligence is heritable, and so are the five major ways in which personality can vary . . . openness to experience, conscientiousness, extroversion‐introversion, antagonism‐agreeableness, and neuroticism. And traits that are surprisingly specific turn out to be heritable, too, such as dependence on nicotine or alcohol, number of hours of television watched, and likelihood of divorcing. Thomas J. Bouchard, “Genetic Influence on Human Psychological Traits,” Current Directions in Psychological Science 13, no. 4 (2004), doi:10.1111/j.0963–7214.2004.00295.x; Robert Plomin, Nature and Nurture: An Introduction to Human Behavioral Genetics (Stamford, CT: Wadsworth, 1996); Robert Plomin, “Why We’re Different,” Edge, June 29, 2016, https://soundcloud.com/edgefoundationinc/edge2016‐robert‐plomin.
220 There’s a strong genetic component: Daniel Goleman, “Major Personality Study Finds That Traits Are Mostly Inherited,” New York Times, December 2, 1986, http://www.nytimes.com/1986/12/02/science/major‐personality‐study‐finds‐that‐traits‐are‐mostly‐inherited.html?pagewanted=all.
220 Robert Plomin: Robert Plomin, phone call with the author, August 9, 2016.
221 more likely to become introverts: Jerome Kagan et al., “Reactivity in Infants: A Cross‐National Comparison,” Developmental Psychology 30, no. 3 (1994), doi:10.1037//0012–16220.127.116.112; Michael V. Ellis and Erica S. Robbins, “In Celebration of Nature: A Dialogue with Jerome Kagan,” Journal of Counseling and Development 68, no. 6 (1990), doi:10.1002/j.1556–6676.1990.tb01426.x; Brian R. Little, Me, Myself, and Us: The Science of Personality and the Art of Well-Being (New York: Public Affairs, 2016); Susan Cain, Quiet: The Power of Introverts in a World That Can’t Stop Talking (London: Penguin, 2013), 99–100.
221 People who are high in agreeableness: W. G. Graziano and R. M. Tobin, “The Cognitive and Motivational Foundations Underlying Agreeableness,” in M. D. Robinson, E. Watkins, and E. Harmon‐Jones, eds., Handbook of Cognition and Emotion (New York: Guilford, 2013), 347–364.
221 They also tend to have higher natural oxytocin levels: Mitsuhiro Matsuzaki et al., “Oxytocin: A Therapeutic Target for Mental Disorders,” Journal of Physiological Sciences 62, no. 6 (2012), doi:10.1007/s12576–012–0232–9; Angeliki Theodoridou et al., “Oxytocin and Social Perception: Oxytocin Increases Perceived Facial Trustworthiness and Attractiveness,” Hormones and Behavior 56, no. 1 (2009), doi:10.1016/j.yhbeh.2009.03.019; Anthony Lane et al., “Oxytocin Increases Willingness to Socially Share One’s Emotions,” International Journal of Psychology 48, no. 4 (2013), doi:10.1080/00207594.2012.677540; Christopher Cardoso et al., “Stress‐Induced Negative Mood Moderates the Relation between Oxytocin Administration and Trust: Evidence for the Tend‐and‐Befriend Response to Stress?” Psychoneuroendocrinology 38, no. 11 (2013), doi:10.1016/j.psyneuen.2013.05.006.
221 hypersensitivity of the amygdala: J. Ormel, A. Bastiaansen, H. Riese, E. H. Bos, M. Servaas, M. Ellenbogen, J. G. Rosmalen, and A. Aleman, “The Biological and Psychological Basis of Neuroticism: Current Status and Future Directions,” Neuroscience and Biobehavioral Reviews 37, no. 1 (2013), doi:10.1016/j.neubiorev.2012.09.004. PMID 23068306; R. A. Depue and Y. Fu, “Neurogenetic and Experiential Processes Underlying Major Personality Traits: Implications for Modelling Personality Disorders,” International Review of Psychiatry 23, no. 3 (2011), doi:10.3109/09540261.2011.599315.
221 Our deeply rooted preferences make certain behaviors easier: “For example, all people have brain systems that respond to rewards, but in different individuals these systems will respond with different degrees of vigor to a particular reward, and the systems’ average level of response may be associated with some personality trait.” For more, see Colin G. Deyoung, “Personality Neuroscience and the Biology of Traits,” Social and Personality Psychology Compass 4, no. 12 (2010), doi:10.1111/j.1751–9004.2010.00327.x.
222 If your friend follows a low-carb diet: Research conducted in major randomized clinical trials shows no difference in low‐carb versus low‐fat diets for weight loss. As with many habits, there are many ways to the same destination if you stick with it. For more, see Christopher D. Gardner et al., “Effect of Low‐Fat vs Low‐Carbohydrate Diet on 12‐Month Weight Loss in Overweight Adults and the Association with Genotype Pattern or Insulin Secretion,” Journal of the American Medical Association 319, no. 7 (2018), doi:10.1001/jama.2018.0245.
223 explore/exploit trade-off: M. A. Addicott et al., “A Primer on Foraging and the Explore/Exploit Trade‐Off for Psychiatry Research,” Neuropsychopharmacology 42, no. 10 (2017), doi:10.1038/npp.2017.108.
223 Google famously asks employees: Bharat Mediratta and Julie Bick, “The Google Way: Give Engineers Room,” New York Times, October 21, 2007, https://www.nytimes.com/2007/10/21/jobs/21pre.html.
224 “Flow is the mental state”: Mihaly Csikszentmihalyi, Finding Flow: The Psychology of Engagement with Everyday Life (New York: Basic Books, 2008).
225 “Everyone has at least a few areas”: Scott Adams, “Career Advice,” Dilbert Blog, July 20, 2007, http://dilbertblog.typepad.com/the_dilbert_blog/2007/07/career‐advice.html.
230 most successful comedians: Steve Martin, Born Standing Up: A Comic’s Life (Leicester, UK: Charnwood, 2008).
230 “4 years as wild success”: Steve Martin, Born Standing Up: A Comic’s Life (Leicester, UK: Charnwood, 2008), 1.
231 “just manageable difficulty”: Nicholas Hobbs, “The Psychologist as Administrator,” Journal of Clinical Psychology 15, no. 3 (1959), doi:10.1002/1097– 4679(195907)15:33.0.co; 2–4; Gilbert Brim, Ambition: How We Manage Success and Failure Throughout Our Lives (Lincoln, NE: IUniverse.com, 2000); Mihaly Csikszentmihalyi, Finding Flow: The Psychology of Engagement with Everyday Life (New York: Basic Books, 2008).
232 In psychology research this is known as the Yerkes-Dodson law: Robert Yerkes and John Dodson, “The Relation of Strength of Stimulus to Rapidity of Habit Formation,” Journal of Comparative Neurology and Psychology 18 (1908): 459–482.
233 4 percent beyond your current ability: Steven Kotler, The Rise of Superman: Decoding the Science of Ultimate Human Performance (Boston: New Harvest, 2014). In his book, Kotler cites: “Chip Conley, AI, September 2013. The real ratio, according to calculations performed by [Mihaly] Csikszentmihalyi, is 1:96.”
234 “Men desire novelty to such an extent: Niccolò Machiavelli, Peter Bondanella, and Mark Musa, The Portable Machiavelli (London: Penguin, 2005).
235 variable reward: C. B. Ferster and B. F. Skinner, “Schedules of Reinforcement,” 1957, doi:10.1037/10627–000. For more, see B. F. Skinner, “A Case History in Scientific Method,” American Psychologist 11, no. 5 (1956): 226, doi:10.1037/ h0047662.
235 This variance leads to the greatest spike of dopamine: Matching Law shows that the rate of the reward schedule impacts behavior: “Matching Law,” Wikipedia, https://en.wikipedia.org/wiki/Matching_law.
240 there is usually a slight decline in performance: K. Anders Ericsson and Robert Pool, Peak: Secrets from the New Science of Expertise (Boston: Mariner Books, 2017), 13.
242 “The pundits were saying”: Pat Riley and Byron Laursen, “Temporary Insanity and Other Management Techniques: The Los Angeles Lakers’ Coach Tells All,” Los Angeles Times Magazine, April 19, 1987, http://articles.latimes.com/1987–04–19/magazine/tm‐1669_1_lakers.
242 a system that he called the Career Best Effort program or CBE: MacMullan’s book claims that Riley began his CBE program during the 1984–1985 NBA season. My research shows that the Lakers began tracking statistics of individual players at that time, but the CBE program as it is described here was first used in 1986–1987.
243 If they succeeded, it would be a CBE: Larry Bird, Earvin Johnson, and Jackie MacMullan, When the Game Was Ours (Boston: Houghton Mifflin Harcourt, 2010).
244 “Sustaining an effort”: Pat Riley and Byron Laursen, “Temporary Insanity and Other Management Techniques: The Los Angeles Lakers’ Coach Tells All,” Los Angeles Times Magazine, April 19, 1987, http://articles.latimes.com/1987–04–19/magazine/tm‐1669_1_lakers.
244 Eliud Kipchoge: Cathal Dennehy, “The Simple Life of One of the World’s Best Marathoners,” Runner’s World, April 19, 2016, https://www.runnersworld.com/elite‐runners/the‐simple‐life‐of‐one‐of‐the‐worlds‐best‐marathoners. “Eliud Kipchoge: Full Training Log Leading Up to Marathon World Record Attempt,” Sweat Elite, 2017, http://www.sweatelite.co/eliud‐kipchoge‐full‐training‐log‐leading‐marathon‐world‐record‐attempt/.
245 her coach goes over her notes and adds his thoughts: Yuri Suguiyama, “Training Katie Ledecky,” American Swimming Coaches Association, November 30, 2016, https://swimmingcoach.org/training‐katie‐ledecky‐by‐yuri‐suguiyama‐curl‐burke‐swim‐club‐2012/.
245 When comedian Chris Rock is preparing fresh material: Peter Sims, “Innovate Like Chris Rock,” Harvard Business Review, January 26, 2009, https://hbr.org/2009/01/innovate‐like‐chris‐rock.
245 Annual Review: I’d like to thank Chris Guillebeau, who inspired me to start my own annual review process by publicly sharing his annual review each year at https://chrisguillebeau.com.
248 “keep your identity small”: Paul Graham, “Keep Your Identity Small,” February 2009, http://www.paulgraham.com/identity.html.
251 No one can be rich unless one coin can make him or her so: Desiderius Erasmus and Van Loon Hendrik Willem, The Praise of Folly (New York: Black, 1942), 31. Hat tip to Gretchen Rubin. I first read about this parable in her book, Better Than Before, and then tracked down the origin story. For more, see Gretchen Rubin, Better Than Before (New York: Hodder, 2016).
Little Lessons from the First Law
260 “Happiness is the space between one desire”: Caed (@caedbudris), “Happiness is the space between desire being fulfilled and a new desire forming,” Twitter, November 10, 2017, https://twitter.com/caedbudris/status/929042389930594304.
260 happiness cannot be pursued, it must ensue: Frankl’s full quotation is as follows: “Don’t aim at success. The more you aim at it and make it a target, the more you are going to miss it. For success, like happiness, cannot be pursued; it must ensue, and it only does so as the unintended side effect of one’s personal dedication to a cause greater than oneself or as the by‐product of one’s surrender to a person other than oneself.” For more, see Viktor E. Frankl, Man’s Search for Meaning: An Introduction to Logotherapy (Boston: Beacon Press, 1962).
260 “He who has a why to live for can bear almost any how”: Friedrich Nietzsche and Oscar Levy, The Twilight of the Idols (Edinburgh: Foulis, 1909).
261 The feeling comes first (System 1): Daniel Kahneman, Thinking, Fast and Slow (New York: Farrar, Straus and Giroux, 2015).
261 appealing to emotion is typically more powerful than appealing to reason: “If you wish to persuade, appeal to interest, rather than reason” (Benjamin Franklin).
263 Satisfaction = Liking − Wanting: This is similar to David Meister’s fifth law of service businesses: Satisfaction = perception − expectation.
263 “Being poor is not having too little, it is wanting more”: Lucius Annaeus Seneca and Anna Lydia Motto, Moral Epistles (Chico, CA: Scholars Press, 1985).
264 As Aristotle noted: Aristotle. The “Art” of Rhetoric (Trans. J. H. Freese. Cambridge: Harvard UP, 1926). 1
Thank you to reader Robert for tracking down the source of this quote.