Believe it or not, for 80 years Harvard researchers have studied the question of what is key to a healthy and happy life. In 1938, scientists began tracking 268 Harvard students to try to determine the answer, and today the Harvard Study of Adult Development is still working on the project with the remaining 19 students, who are now well into their 90s. I will let the current study director, Robert Waldinger, share with you their surprising findings in this fascinating 12 minute TED talk.