Since 1938, the Harvard Study of Adult Development has followed two groups of men. One is a group of 456 boys from Boston’s most troubled families and roughest neighborhoods. The other consisted of 268 Harvard College students, chosen by a professor of hygiene specifically for their potential to become healthy, well-adjusted adults. The focus of the longitudinal study has been to discern the factors that best predict a long, healthy life.
The researchers who have followed these young men have maintained a stunning 84 percent participation rate over eight decades. They have visited homes, spoken to parents and siblings, tracked medical exams, and followed marriages and careers. The study, which is currently tracking a second generation of participants, has produced a wealth of significant data. However, in a recent article published in The Wall Street Journal, director Dr. Robert Waldinger and associate director Dr. Marc Schulz pointed to the most significant contributing factor for physical health, mental health, and longevity.