Between 1939 and 1942, Harvard University recruited 268 of its healthiest, most promising undergraduates for a revolutionary study of the human life cycle. Vaillant, the study’s director, took the measure of these men. The result was this classic, which poses fundamental questions about individual d...

Between 1939 and 1942, Harvard University recruited 268 of its healthiest, most promising undergraduates for a revolutionary study of the human life cycle. Vaillant, the study’s director, took the measure of these men. The result was this classic, which poses fundamental questions about individual differences in confronting life’s stresses.