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Scroll back through your phone’s contact list and you’ll probably find a graveyard of names. A university housemate, an old workmate, the friend from that summer job, people you once talked to every week and haven’t messaged in years.
At 60, it’s easy to look at that list and feel a pang of guilt, as if you’ve let friendships slip through your fingers. Research suggests you’re far from alone. For most people, social circles follow a predictable arc, and it begins shrinking surprisingly early.
Three million phone users
In 2016, a team led by Kunal Bhattacharya of Aalto University in Finland, working with Oxford anthropologist Robin Dunbar, analyzed a year of anonymous phone records from a European mobile network. The data, collected in 2007, covered 3.2 million users whose age and gender were known.
The researchers counted how many different people each person regularly called, then looked at how that number changed with age. Phone calls aren’t a perfect measure of friendship, but they’re a good indicator of who people actively keep in touch with.
The peak at 25
The results showed a clear pattern. The number of connections reached a maximum at around age 25, for both men and women.
After that, social circles started to shrink. The decline leveled off in the late 40s, staying fairly stable until the mid-60s, a period when many people juggle children, aging parents, in-laws and friends. After that, the numbers began to fall again.
There were differences between the sexes too. Young men tended to have more contacts than young women. But from around the late 30s, the pattern reversed, and women became more connected than men.
Why it happens
The shrinking circle isn’t a personal failing. It largely reflects how life changes.
In our early 20s, many people are surrounded by others their own age, at university, in shared houses, in first jobs and in busy social scenes. There’s more free time and fewer competing commitments. After 25, people often settle into long-term relationships, start families and focus more on careers. Time becomes limited, and the people closest to us naturally get more of it.
Later in life, retirement, moving house, health changes and the deaths of friends can all shrink social networks further.
The brain’s social budget
Dunbar is best known for the idea that human brains can only manage a limited number of meaningful relationships, often summarized as around 150 people. Within that, he suggests, we tend to have about five very close relationships, around 15 good friends, and larger outer circles of looser contacts.
Neuroscience offers some support. In a 2011 study published in Nature Neuroscience, Kevin Bickart and colleagues found that adults with a larger amygdala, a brain region involved in reading social and emotional cues, tended to have larger and more complex social networks. Other research has linked the size of certain prefrontal brain regions to the number of friends people maintain.
Friendships take mental effort, as well as time. Keeping track of who’s who, what’s happening in their lives and how we feel about them requires real brain power. With limited time and attention, something has to give, and it’s usually the outer circles.
Fewer friends, but often closer ones
A shrinking network doesn’t automatically mean a lonelier life. Stanford psychologist Laura Carstensen has found that as people age, they tend to drop casual acquaintances while holding on to their closest relationships. Many older adults report that their emotional lives become more satisfying, not less.
Still, there’s a real risk at the far end of the curve. Persistent loneliness has been linked to chronic stress, which keeps the body’s HPA axis switched on, along with poorer health. The goal isn’t to recreate the social life you had at 25, but to make sure the circle doesn’t shrink too far.
What you can do
The research suggests a few simple steps. Reach out to people you’ve lost touch with, even briefly. Studies show people tend to underestimate how much others appreciate hearing from them.
Join groups built around shared interests, such as clubs, classes or volunteering, where regular contact happens naturally. And invest in the relationships you already have, especially the closest ones.
If you look up at 60 and notice fewer names in your phone, it doesn’t mean you’ve done something wrong. It means you’ve lived a full life, and you still have the chance to decide who you want close.
