Who’s in Your 5? Scientists Say the Friends Closest to You Are the Ones That Help You Live Longer

Three scientists explain which friendships move the needle most and how to build them when life stops making it automatic.

You don’t just get by with a little help from your friends—you actually live longer.

In a 2023 study of almost 13,000 people, those with high “friendship scores” in a 2023 study had a 24 percent reduced risk of all-cause mortality[awl kawz mawr-tal-i-tee]nounThe risk of death from any cause.Learn MoreClose—science-speak for death—and a 19 percent reduction in stroke risk over the test period. They may keep you younger, too: In an October 2025 study, scientists found that people with higher levels of social support had slower speeds of epigenetic aging according to age clocks, and had lower levels of IL-6, a protein linked to chronic inflammation[in-fluh-mey-shuhn]nounYour body’s response to an illness, injury or something that doesn’t belong in your body (like germs or toxic chemicals).Learn MoreClose.

Gobs of other studies have found health and healthspan[helth-span]nounThe number of years you live in good health, free from chronic illness or disability.Learn MoreClose benefits of having buddies. People with friends and close confidants:

• Are less likely to have depression and anxiety.
• Are less likely to die from cardiovascular disease.
• Have less blood pressure reactivity when talking to those friends.

Not having friends to confide in, on the other hand, can have devastating consequences: Scientists have learned that a lack of social connection is almost as bad for your health as smoking a pack of cigarettes per day. 

The problem: As we age, our circle of friends tends to shrink. That’s been found in large, population-wide research studies, but it also just tracks with common sense, says E. Ayn Welleford, Ph.D., an associate professor of gerontology at Virginia Commonwealth University who studies friendship.

“We’re used to most of our friendships just kind of falling into our laps based on proximity because of life: We’re in school. We’re raising kids and hanging out with a group of people at soccer games. We’re at work,” she tells us. But as we age, those opportunities start to dry up.

To find out what types of friendships will help Super Agers live better lives, plus how many and how to build and maintain them, I spoke with Welleford and two other experts:

• Athena Aktipis, Ph.D., an associate professor in psychology at Arizona State University who studies human generosity and how people cooperate.
• Gillian Sandstrom, Ph.D., an associate professor in the psychology of kindness at the University of Sussex, and the author of Once Upon a Stranger: The Science of How “Small” Talk Can Add Up to a Big Life. 

Building the Right Types of Friendships

Focusing on whether friendships are helpful to your health can feel a little transactional. And there’s a bit of a history to this in psychology research: It’s called “social exchange theory,” and it’s an idea that relationships are tallies of costs and benefits. But there’s more nuance to real-life connection, Aktipis points out.

People choose friends because they can reap benefits from the friendship, she says, like fun or intellectual stimulation, but we also interact with people in what are called “risk-pooling” ways: When one of the group is in need, we reach out and help out, even if there’s no reciprocal benefit. This can be giving someone a place to stay if there’s a flood, bringing food over when they’re sick, or even just getting together to let the person who’s suffering unload their emotions. Basically: These types of friends have our back, and we have theirs.

Risk-pooling relationships were one of the key factors in having a higher “friendship score” in the 2023 study that found people with good friends live longer. Those with the highest friendship scores:

• Had more close friends: An average of 7.8, versus 1.6 for those with the lowest scores.
• Saw those friends more than one time per week: Eighty-six percent saw close friends at least once per week, compared to just 9 percent for the lowest-scoring group.
• And received the most social support from their friend group.

To reap the benefits of a high friendship score of your own—and to have friendships that aren’t too transactional—you’ll want to have a few different kinds of friends:

Friends who are confidants: These are friends that you can tell anything, Welleford says, without fear of judgment. 

Friends you can spend time with without an agenda: One way to tip the balances of friendships from transactional to more risk-pooling in nature, Aktipis suggests, is to find friends with whom you can do… nothing.

“People do want to have social relationships where you really just enjoy being together without it being about any particular agenda,” she says. These friendships are the type where you can simply “waste time” together.

This, she admits, is not always easy to do: While this type of “let’s just hang” friendship is common when we’re young, they’re tougher as we become more busy with age. Building these types of friendships can take time, too: In a study from the University of Kansas, researchers found that it can take 200 hours of time together for someone to progress from an “acquaintance” to a close friend.

Friends with whom you touch base often: In high-scoring friendship assessments, these relationships include touching base once per week or more. Some of these types of friendships form your immediate social group, or your “5,” according to Welleford’s method of thinking of friendship circles (more on that below).

But they don’t have to be close: In a 2020 study, British researchers paired older adults with volunteers who called once per week for a friendly conversation. Within three months, the older adults had lower levels of stress hormones, and they slept better.

And some friends who are geographically close: Friends who are “weak ties” that live near you can help with mortality just as much as strong ties who are far away, says Sandstrom. People with more local friends in their area are more likely to stay active; these are the ones extending invitations, creating a sense of belonging, and opening doors to more experiences. In another study from Finland, people with larger numbers of “weak ties” but fewer “strong ties” were no less likely to experience early mortality than those with lots of both kinds of friends.

Who’s in your 5? Defining your close friendships

When thinking about your social relationships, don’t think of it as your “friend circle,” but as multiple friend circles, Welleford says. Her preferred method divides your friends into circles of 5, 15, 50, and 150.

• Your “5” are your immediate social group: These are people you engage with every week, and might include your partner, your best friend, siblings, and others. (This group may be larger than 5 people, but usually tops out under 10.)
• Your “15”: “These are people who, if you got sick or had a death in the family, would bring you casseroles or take care of your dog for you.”
• Your “50” are people who would make up the guest list for a big event you might hold for a milestone anniversary or other occasion.
• And your “150” are basically all the people you can keep track of, in total. This, Welleford says, is about the upper limit of people you can really know. This theory is based on “Dunbar’s Number,” named for British anthropologist Robin Dunbar.

The people in your closest sphere—your “5”—are the most important to your life and well-being, Welleford emphasizes. And so it’s the area where you need to put in the most time and work by reaching out, staying in touch, and putting in active effort to stay connected in our current environment, where our mobile devices can make us more isolated.

Your “5” may also be where you notice something’s missing in your social life, she adds. Her advice: Write down who’s in this closest circle, and the roles they fill in your life.

For Welleford, the “5” could include a confidant that you can tell anything without judgment, a cheerleader who helps boost your confidence, a “permission-slip giver” who helps you let yourself off the hook when you want to skip out on something you “should” do. They could even be someone who keeps you accountable: Welleford says that one of her friends that she often sees at workout classes will check in with her if she misses a class, keeping her on track to meet her health goals.

These roles will be different for every friend group. Once you’ve written down and analyzed what is provided by your “5”, the next step is to identify what kinds of relationships are missing from this group. It could be that you’d like someone to exercise with, or someone to fill the confidant role outside of your romantic relationship (a role that, Welleford tells us many men in particular are missing). 

How to Do It: Scientists’ Tips for Making and Maintaining Close Friendships as We Age

Since our friendships aren’t as automatic as we age out of school and other areas that default us into new friendships, building new relationships and maintaining (or rekindling) old ones comes down to effort, Welleford explains. 

“You have to be intentional,” she says. “But we’re not used to that.”

Making and maintaining friendships is kind of like dating, she points out. If you’re lucky enough to have a romantic partner, you may be out of practice in that arena—and out of practice with the vulnerability and rejection it requires.

The answer to being out of practice, Sandstrom says, is practice. To reduce the awkwardness and get comfortable being vulnerable, follow these expert strategies:

Talk to strangers more often

Sandstrom used to be so shy that when her name was called over the intercom of a plane, she was too bashful to push her call button to let the crew know she was onboard. One way she’s become more comfortable is talking to strangers, which has become the crux of her research.

In studies, she’s had volunteers go out on “scavenger hunts” where they find people of a certain type to talk to over the course of a week—it might be people wearing a hat, or a certain color of jacket. By striking up conversations with these strangers, the participants become more comfortable in conversation in general, and gain more trust in people overall.

Rekindle old friendships with a moment of feeling awkward

It can be simpler to rekindle an old friendship than start a fresh one, Welleford says. But it can also feel awkward. If you fell out of touch and haven’t talked in a while, it’s a vulnerable leap to touch base out of the blue.

Welleford’s advice: Come up with a low-stakes reason. If there’s a friend you’ve wanted to reconnect with, find a video or article or something else you’ve seen recently that relates to your friendship, and send it to them. “Then it’s as easy as ‘I saw this thing the other day and I thought of you, how have you been?’” Starting the conversation back up is the hardest part, and that simple connection can grease the wheels.

Keep the stakes low

When you’re trying to take a friendship to the next level, as in the world of dating, you’ve sometimes got to make the “second move,” Welleford says, going from a single conversation to meeting up again.

Both Welleford and Sandstrom suggest keeping the stakes low when doing this.

With a new friend, Sandstrom adds, relate it directly to the activity that brought you together. If you continue to run into and talk to a neighbor while walking your dog, for example, you might start by casually arranging to walk together again at the same time the following week.

Welleford suggests connecting it to an activity you’re both interested in: “If you see someone at an event and say, ‘hey, I know you’re into gardening. There’s a class at Snead’s [garden center] that’s going to be happening if you want to go,’” she advises. When it’s something you’re already doing, there’s less pressure on them when you ask them to come.

This, she theorizes, is the magic of pickleball’s impact on people’s social lives: It’s connected to an activity you’re already doing, and setting up a match is a low stakes reach-out.

Imagine the worst-case scenario:

When reaching out to someone, either online or in person, being vulnerable can be scary. But, Sandstrom says, it helps to envision the worst-case scenario.

“What’s the worst that could happen?” she asks. The other person might say no, and you might feel awkward for a moment. “It’s not as high stakes as you feel like it is.”

The benefits, on the other hand, can be huge: More healthspan and better cardiovascular markers, sure. But even better, you could experience more deep, meaningful relationships, and more life satisfaction. Those benefits, the studies and our experts say, are worth your courage.

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