Gretchen Rubin is the co-host of “Happier with Gretchen Rubin.” One of the most thoughtful and influential voices on the subject of happiness, habits, and human nature, she’s the author of several New York Times bestsellers, including The Happiness Project and Better Than Before. Her latest book, The Four Tendencies, explores a personality framework she created that divides people into four types. She lives in New York City with her family.