What if we could watch entire lives as they unfold through time? 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 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, write Robert Waldinger and Marc Schulz, the director and associate director of the study. Contrary to what many people might think, it’s not career achievement, or exercise, or a healthy diet. ⁠ ⁠ Close personal connections are significant enough that if all 85 years of the Harvard Study were boiled down to a single principle for living, it would be this: Good relationships keep us healthier and happier. If you want to make one decision to ensure your own health and happiness, it should be to cultivate warm relationships of all kinds, Waldinger and Schulz write.⁠ ⁠ Read more from their essay at the link in our bio.⁠ ⁠ 📷: @tonjethilesen for @wsjphotos