"Good relationships keep us happier and healthier."

quotes:

In 2003, the psychiatrist Robert Waldinger accepted a new job at Harvard, where he had long been affiliated, overseeing one of its most prized research projects. . . . Waldinger, the fourth steward of the Harvard study, was moved by the consistency of his own research. . . .

 Much of it added up to one key insight: “The clearest message that we get from this 75-year study is this: Good relationships keep us happier and healthier. Period,” he said in a TED Talk in 2015. Strong, long-term relationships with spouses, family and friends built on deep trust — not achievement, not fortune or fame — were what predicted well-being. Waldinger had worried that his big reveal was so intuitive that he would be laughed off the stage; instead, the talk is one of TED’s most watched to date, with more than 40 million views.

"How Nearly a Century of Happiness Research Led to One Big Finding" By Susan Dominus, May 1, 2025, New York Times,
https://www.nytimes.com/2025/05/01/magazine/happiness-research-studies-relationships.html

This "key insight" is actually 2,000-year-old wisdom:

Gospel
John 13:34-35 NRSV
Jesus Christ: "I give you a new commandment, that you love one another. Just as I have loved you, you also should love one another. By this everyone will know that you are my disciples, if you have love for one another."