Connection is a longevity practice

A Boston study, since 1938.

Here in Boston, the Harvard Study of Adult Development has followed the same group of men, and later their families, for more than 80 years. Its directors report that the people most satisfied in their relationships at 50 were the healthiest at 80, and that relationship satisfaction predicted healthy ageing better than midlife cholesterol.¹ The original group was all men and mostly white, so it cannot speak for everyone. But its message has been echoed by far larger studies.

What 148 studies found.

In 2010, researchers combined 148 studies following 308,849 people for an average of seven and a half years. People with stronger social relationships had about 50% greater odds of surviving the follow-up period.² The authors described the effect as comparable to quitting smoking.

A follow-up analysis of more than three million people found that social isolation, loneliness and living alone were each linked to a higher likelihood of early death: about 29%, 26% and 32% respectively.³ The words matter. Isolation means having few connections. Loneliness is the feeling that the connections you have are not enough. You can feel lonely in a crowded life, and content in a quiet one.

You can feel lonely in a crowded life, and content in a quiet one.

A public-health story.

In 2023, the US Surgeon General issued an advisory on loneliness and isolation, noting that about half of American adults report feeling lonely, and comparing the mortality risk of lacking social connection to smoking up to 15 cigarettes a day. The advisory also cites national survey data showing that time spent in person with friends fell from about 60 minutes a day in 2003 to 20 in 2020.⁴ Before the pandemic, 24% of Americans aged 65 and over were already socially isolated.⁵ Worldwide, the WHO Commission on Social Connection estimates that one in six people is affected by loneliness, linked to about 871,000 deaths a year.⁶

Why the body notices.

Loneliness seems to keep the body in a low-grade state of alert. Lonelier people have shown a larger morning stress-hormone response, blood pressure that climbs over time, more activity in inflammation-related genes, and lighter, more broken sleep.⁷ Across four large US samples, people with more social ties had lower inflammation and blood pressure, and in later life the link between isolation and high blood pressure was stronger than the link with diabetes.⁸

What helps, honestly.

The evidence on solutions is more modest than the evidence on risk. In randomized trials, programs designed to reduce loneliness had small effects on average. The most promising approaches helped people notice and gently challenge the habit of withdrawing, though only a few trials tested them.⁹ Volunteering among adults over 55 was linked to about 24% lower mortality after accounting for health and other differences.¹⁰ And the simplest advice from public-health bodies is also the most practical: reach out to a friend, greet a neighbour, join a group, put the phone away when you are together.⁶

Connection, as a practice.

We think of connection the way we think of movement. It works best when it is scheduled, repeated and low-stakes: a standing walk with a friend, a weekly call, a class where you see the same faces, a place where people know your name. None of it has to be grand. Like every part of longevity, it is the steady rhythm that matters. Forever is a practice, and so is staying close.

How to read these numbers.

Almost all of this research is observational. Illness, depression or financial strain can cause isolation as well as follow from it, so the arrows run both ways. No trial has shown that a social program adds years to life. What the evidence does show, consistently and across many countries, is that people with strong, satisfying relationships tend to live longer and healthier lives.