Your overall happiness level increases with age, with more people in their 80s reporting being very happy, compared to their younger counterparts. The least happy bunch were the baby boomers, being those people born between 1946 and 1964. The lead researcher Yang suggests this is due to disappointment in not getting what they had hoped for in life. Interviews of between 1500 and 3000 people were conducted each year between the years 1972 and 2004 by the University of Chicago's National Opinion Research Centre.