Price of happiness in every country revealed mirror.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from mirror.co.uk Daily Mail and Mail on Sunday newspapers.
The study tracked the lives of 724 Boston men for 80 years from 1938 and then went on to study their Baby Boomer children. DailyMail.com spoke to its lead researcher.