What years of research says about happiness

Wealth, fame and success still don’t make us happy — but strong relationships do.

That has been the consistent message from the Harvard Study of Adult Development — the longest-running scientific study of adult life in the world.

The study began in 1938, tracking the health and well-being of 724 young men — 268 Harvard College sophomores and 456 boys from some of Boston’s toughest inner-city neighborhoods. Researchers interviewed their parents, conducted medical exams and followed the participants closely for the rest of their lives.

Nearly 90 years later, researchers are now studying more than 1,300 of the original subjects’ offspring and their spouses. The findings remain rock-solid: Good relationships keep us healthier and happier. Period.

Harvard psychiatrist Robert Waldinger, the