A Complete Summary of The Willpower Instinct: How Self-Control Works, Why it Matters, and What You Can Do About it. The Willpower Instinct is a book written by Kelly McGoingal. The author is a Ph.D., which is visible immediately after the readers start reading the book, since the book is filled with information the author used from her research. The main purpose of this book is to show its readers why we lose self-control and what is that each of...