What if the secret to longevity wasn’t in the mind or the gut — but in the heart?

Speaking at the inaugural New York Times Well Festival on Wednesday, psychiatrist and researcher Dr. Robert Waldinger announced he and his team were “shocked” by “the biggest predictor of who was going to live long and stay healthy.”

Waldinger, the director of the Harvard Study of Adult Development — the longest-running scientific study of adult life — revealed the predictor was “how connected you were to other people and particularly the warmth of your connection to other people.”