Will you have fewer friends after Covid lockdown?

As many countries tentatively loosen their corona restrictions, some of us are feeling anxious. Have my social skills gotten rusty from long quarantines and lockdowns? Have my friendships gone stale? Will I still have my old clique to return to? Have my social circles frayed or shrunk?

To get a scientific perspective, I put these questions to Robin Dunbar, a British anthropologist and evolutionary psychologist. I’ve kept tabs on his research for almost three decades, ever since he wrote a groundbreaking paper in 1992. Dunbar discovered a remarkably stable ratio across all species of primates between the size of their neocortex and their social group: the larger the brain, the larger the community.

This makes sense. Surviving and thriving in groups requires vast amounts of cognitive power. Who likes and dislikes me? Have those two slept together? Is that other guy jealous? Does that one over there remember my slight from two months ago? Could I turn that rival into an ally? And so forth.

This became controversially known as the “social brain hypothesis” — or the “Machiavellian intelligence hypothesis,” which sounds quite sinister. But other research emphasizes that our cognition also makes us “prosocial” and caring toward others. Hence the abundant grooming that primates do to get the endorphins flowing. For us that usually means hugging.

One nuance in Dunbar’s theory is that primate groups come in different categories. Humans, for instance, tend to be intimately close with only about five other people. They also form “bands” of about 40 — such as hunting parties, platoons or teams, say — and much larger “tribes,” numbering in the thousands. But the average size of a human “community” is, and always has been, about 150.

It’s astonishing how stable this so-called “Dunbar number” is. It describes the average upper limit of hunter-gatherer groups, medieval villages, online gaming communities, Christmas card lists, church congregations and more. When human groups exceed the number — as when companies grow to more than 150 employees — our innate cognition usually becomes inadequate and we need bureaucracy to organize ourselves.

In 2009, when online social networks were still new to many of us, I wondered whether technology could increase the Dunbar number, so I asked Facebook to crunch some data. No, it turned out. Facebook and its ilk may let us manage what is in effect an enlarged Rolodex of acquaintances. But they can’t raise the limit on quality relationships we maintain, because that appears to be biological.

But what about the pandemic and all the lockdowns it made necessary? Such unnatural periods of social isolation must wreak havoc on the primate psyche. I doubt that other apes and monkeys would survive a prolonged quarantine. Bonobos need constant sexual stimulation to maintain group harmony and cohesion. Other primates do less of that, but your average chimp, lemur or baboon would also wither without social contact. Their communities would unravel.

Monkeys don’t have Zoom, of course, whereas we do. Still, our whizz-bang social media are at best imperfect and partial substitutes for in-the-flesh grooming. On Zoom you can see people’s eyes, but you can’t tell what they’re gazing at, a crucial signal in group dynamics. You can have only one person speaking at a time. You can’t scent pheromones. And you can’t hug, poke or otherwise get oxytocin flowing.

Things like Zoom only “slow down the rate of decay in the absence of face-to-face contact,” Dunbar told me in an email. “They won’t stop a friendship becoming an acquaintanceship, someone I once knew.”

The absence of social contact probably won’t affect our inner layer of intimate contacts. But in our wider communities, Dunbar thinks, “when you meet again in person, there will be just an edge of uncertainty as to whether the relationship is still the same.” Many may no longer be.

But that’s fine, Dunbar reassures me. The effect is only temporary and requires some social “renegotiation.” This could mean that interesting changes are afoot in the coming months and years, within companies, neighborhoods, schools and other communities. Eventually, though, we’ll all settle back down to our natural groupings of about 150 people — fortunately, that’s fixed by our brains.