Triumphs of Experience: The Men of the Harvard Grant Study by George E. Vaillant.

The book details the findings of the longest-running longitudinal study of human development ever undertaken, which began in 1938 and followed the physical and emotional health of over 200 Harvard undergraduate men into their nineties. Key findings include: •Strong relationships are the most important contributor to lifelong happiness and success. •People continue to mature and develop throughout their entire lives, challenging the idea that character is set in adolescence. •While a warm childhood is a lifelong source of strength, recovery from a difficult childhood is possible, demonstrating significant human resilience. •Physical aging after 80 is determined less by heredity than by healthy habits formed before age 50. •Alcoholism was found to be a major disruptor of health and happiness among the subjects, accounting for more than half of the divorces in the study.