The Willpower Instinct: How Self-Control Works, Why It Matters, and What You Can Do To Get More of It

THE LAST WORD
In the spirit of scientific inquiry, I always end my Science of Willpower course by asking the students
what stands out to them from everything they’ve observed and every experiment they’ve tried. More
recently, a scientist friend of mine suggested that the only reasonable conclusion to a book about
scientific ideas is: 
Draw your own conclusions.
So as tempting as it is to have the last word, I’ll
exercise my “I won’t” power, and ask you instead:
• Has your thinking about willpower and self-control changed?
• Which willpower experiment was the most helpful?
• What was your big a-ha moment?
• What are you going to take with you?
As you move forward, keep the mind-set of a scientist. Try new things, collect your own data, and
listen to the evidence. Stay open to surprising ideas, and learn from both your failures and your
successes. Keep what works, and share what you know with others. With all our human quirks and
modern temptations, this is the best we can do—but when we do it with an attitude of curiosity and
self-compassion, it is more than enough.

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ACKNOWLEDGMENTS
Everyone I’m related to got thoroughly thanked in the last book, and nothing has changed—I’m still
grateful for a lifetime of support. So thanks now to some new people, who made this book possible:
To my agent, Ted Weinstein, who every author should be so lucky to have as an advocate. He gets
credit for shaping the proposal, helping the book find just the right publisher and editor, and making
sure I wasn’t procrastinating on my deadlines.
To the entire publishing team at Avery, and especially my editor, Rachel Holtzman, for championing
the book, providing brilliant editorial guidance, and (no small matter) appreciating the humor of a
study that asks preschoolers to resist marshmallows. I hate to think what might have become of this
book in the hands of someone who didn’t love science.
To readers of my first drafts: Brian Kidd, who was unfailingly enthusiastic about every word and
laughed at all the jokes, and Constance Hale, whose insightful feedback helped me clean up the mess.
To illustrator Tina Pavlatos, of Visual Anatomy Limited, for the wonderful brain pictures in this
book, and for demonstrating exceptional patience when I kept asking for a slightly different angle on
the medial prefrontal cortex.
To all of the scientists who talked with me via phone, e-mail, or in person, either directly for the
book or over the years helping me shape my understanding of the science, including Jo Barton, Sarah
Bowen, Daniel Effron, James Erskine, Hal Ersner-Hershfield, Matthew Gailliot, Philippe Goldin,
James Gross, Kate Janse Van Rensburg, Brian Knutson, Jason Lillis, Eileen Luders, Antoine Lutz,
Traci Mann, Benoît Monin, Kristin Neff, Robert Sapolsky, Suzanne Segerstrom, Brian Shelley, and
Greg Walton. Deep gratitude for your contributions to the field, and if I erred in my description of the
nuances of your work, I apologize.
To the folks at Stanford who have supported my teaching over the years: a special thanks to
Stanford Continuing Studies for nurturing “The Science of Willpower,” especially Associate Dean
and Director Dan Colman, who first approved the course idea; and to the Stanford Center for
Teaching and Learning, the School of Medicine’s Health Improvement Program, the Stanford Center
for Compassion and Altruism Research and Education, and the Psychology One Program for giving
me the tools, opportunities, and encouragement to focus on becoming a better teacher.
The last and largest “thank you” goes to all the students who took the course “The Science of
Willpower,” without whom there would be no book. Especially to those of you who asked tough
questions, bravely shared your embarrassing stories in front of a lecture hall full of strangers, and
even brought in homemade fudge on the last night of class so we could all practice—or abandon—
willpower in celebration.

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NOTES

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