Gretchen Rubin is the New York Times bestselling author of several books about happiness, habit and human nature. Her books, including The Four Tendencies, Better Than Before, Happier at Home, and The Happiness Project, have sold over 3.5 million copies worldwide. Gretchen also has a popular blog and podcast, called Happier. Previously, she received a law degree from Yale and clerked for U.S. Supreme Court Justice Sandra Day O'Connor.  Topics in this episode include happiness engineering, how to make and break habits, why habits are highly personal and Gretchen's four tendencies framework, willpower, and the effects of clutter on the mind.   FitMind App: http://bit.ly/afitmind  Website: www.fitmind.co