The Naturals might be the most challenging and rewarding book I’ve ever written. I’m grateful to have had the opportunity to combine my love of psychology and knowledge of cognitive science with my passion for YA, and I owe a major debt of gratitude to the many people who helped me along the way.

Major thanks go to my editor, Catherine Onder, whose passion for this project and keen eye helped me make this a book I couldn’t have written on my own. My agent, Elizabeth Harding, has been with me every step of the way for a dozen books now, and I feel continually lucky to have her on my side. My UK agent, Ginger Clark, and everyone at Quercus Books have been such supporters of this project from its conception—I’m so grateful to have such tremendous teams behind the book on both sides of the pond. And, of course, I owe huge thank-you’s to everyone at Disney-Hyperion, including Dina Sherman (for—among other things—two-stepping!). Thanks, too, to my film agent, Holly Frederick, and to Lorenzo De Maio for asking questions that made me go further into this world.

Writing this book involved a lot of research. I owe particular debts to the memoirs of FBI profiler John Douglas, and to the empirical research of Paul Ekman, Maureen O’Sullivan, Simon Baron-Cohen, and many others.

As a writer—and a person—I’ve been blessed with an incredible support system, and I’ve never relied on it as much for my own sanity as I did in the writing and editing of this book. A big thank-you to Ally Carter, BFF extraordinaire, for talking me down off many a cliff and for reading an earlier draft of this book. Thanks also to Sarah Cross, Sarah Rees Brennan, Melissa Marr, Rachel Vincent, BOB, and so many others for their friendship and support through the ups and downs of publishing and the creative process.

The writing and revising of this book spanned the last year of my PhD and my first year as a college professor. Thank you to my cohorts and advisors at Yale, and to everyone in the psychology department at the University of Oklahoma for being so welcoming my first year as a professor there—and so supportive of my books! I’d also like to thank my incredible students, especially those in my Cognitive Science of Fiction and Writing Young Adult Fiction classes last spring. Teaching you has been such an amazing experience, and I’m a better writer for it!

Finally, thanks—as always—go to my incredible family. Mom, Dad, Justin, Allison, and Connor, I love you more than words can say.