Dr. Ed Diener
For his fundamental research on the subject, Diener is nicknamed Dr. Happiness. Researchers he has worked with include Daniel Kahneman and Martin Seligman.
Dr. Diener is past president of three scientific societies: the International Society for Quality of Life Studies, the International Positive Psychology Association, and the Society for Personality and Social Psychology. He is a fellow of five professional societies, including the Association for Psychological Science, American Psychological Association, and International Society for Quality of Life Studies, Society for Personality and Social Psychology, and Experimental Psychology.