What is the secret to human happiness?

Dr Robert Waldinger has been studying human happiness and the secret to it for decades. He is Clinical Professor of Psychiatry at Harvard Medical School, and Director of the the Harvard Study of Adult Development. That study first began in 1938 with 228 Harvard students with researchers collecting data on their medical and mental health. In the 1970s, another 450 inner-city residents joined the study. It is the world's longest-running research into happiness and suggests friendship and connections help us to live longer and be happier. Dr Robert Waldinger has co-authored a book The Good Life and How to Live It with Marc Schulz and has presented a TED Talk which has over 24 million views.