Yes. There is strong, consistent scientific evidence that social connection is linked to health and to how long people live. It comes from studies of hundreds of thousands of people followed over years, and it has held up across reviews and countries, though its size depends on how connection is measured. What that evidence mostly is not is proof of cause. Nearly all of it is observational: researchers measured people's relationships, then waited to see what happened to their health. That design can show a large, repeated link. On its own it cannot show that the relationships produced the outcome. So the honest answer comes in three parts: what is well established, what is suggestive, and what is not known. (If you want the definition first, it lives on our What Is Social Wellness page; this piece is only about...