George E. Vaillant 
Triumphs of Experience [EPUB ebook] 
The Men of the Harvard Grant Study

At a time when people are living into their tenth decade, the longest longitudinal study of human development ever undertaken offers welcome news for old age: our lives evolve in our later years and often become more fulfilling. Among the surprising findings: people who do well in old age did not necessarily do so well in midlife, and vice versa.