From Robert Waldinger and Marc Schulz writing at the WSJ:
... What if we could study people from the time that they were teenagers all the way into old age to see what really matters to a person’s health and happiness, and which investments really paid off? For 85 years (and counting), the Harvard Study of Adult Development, which we now direct, has tracked an original group of 724 men and more than 1,300 of their male and female descendants over three generations, asking thousands of questions and taking hundreds of measurements to find out what really keeps people healthy and happy.
Through all the years of studying these lives, one crucial factor stands out for the consistency and power of its ties to physical health, mental health and longevity. Contrary to what many people might think, it’s not career achievement, or exercise, or a healthy diet. Don’t get us wrong; these things matter. But one thing continuously demonstrates its broad and enduring importance: good relationships.
In fact, close personal connections are significant enough that if we had to take all 85 years of the Harvard Study and boil it down to a single principle for living, one life investment that is supported by similar findings across a variety of other studies, it would be this: Good relationships keep us healthier and happier. Period. If you want to make one decision to ensure your own health and happiness, it should be to cultivate warm relationships of all kinds. ...
[I]t wasn’t their middle-aged cholesterol levels that predicted how they were going to grow old; it was how satisfied they were in their relationships. The people who were the most satisfied in their relationships at age 50 were the healthiest, mentally and physically, at age 80....
[F]or older people, loneliness is twice as unhealthy as obesity, and chronic loneliness increases a person’s odds of death in any given year by 26%....
