| If you were going to invest now in your future self, what would you focus on? One of the world's longest running health studies sought to find the answer. The Harvard study of adult development began in 1938. It followed two groups of young men, some from inner city Boston and others who studied at Harvard. Their lives gave researchers evidence that our relationships with others keep us happy and healthy. Dr. Robert Waldinger, the fourth director of the study, joins "CBS This Morning" to discuss the findings.