It's the start of a fresh year, and optimism is in the air. But if you want happiness to extend far beyond your New Year's resolution, Robert Waldinger says you can take some inspiration from the longest-running study of happiness out there. He’s a psychiatrist who runs the Harvard Study of Adult Development. The longitudinal research has followed individuals and their families for nine decades. He shares what makes people happiest in the long run and how their work factors into that. Waldinger is the author of the new book "The Good Life: Lessons from the World’s Longest Scientific Study of Happiness."