How the science of friendships can help make yours better

Meaningful friendships might feel like something that should come naturally. We enjoy people’s company or we don’t; we find the same things funny or struggle to laugh together. But the unwritten rules of different kinds of friendship can be surprisingly tricky to navigate. Over the past decade, though, careful research has begun to unravel not only how significant such relationships are for our well-being but also how to ensure the right ones thrive.

Jeffrey Hall, director of the Relationships and Technology Lab at the University of Kansas, is one researcher investigating how to foster friendship. He says it is best to think of our friendships as lying on a continuum – from mere acquaintances and friends of friends to our besties who are always there for us.

“A minimum standard is that two people like each other, and that there is a frequency of communication that allows for the flourishing in that relationship,” he says. “We expect a sense of trust and reliability, the expectation we can confide our secrets, and that they are people who we genuinely enjoy spending time with and will prioritise over others.”

You might have noticed that time investment plays a big role in Hall’s definitions. In a series of surveys, he asked participants who had recently moved to a different city to chart the development of their new social lives. He found that people needed to spend between 57 and 164 hours with someone before they could be considered a “friend”, and roughly 200 hours together to become a “good” or “best” friend.

The type of time spent together is vital, too. “It’s involving the person in the day-to-day affairs of your life – eating, drinking, playing, hanging out – because you want to have them there, and sharing those things makes them better,” says Hall, who is the co-author of a new book, The Social Biome, exploring these themes. Being forced into each other’s company through work or study, in contrast, did nothing for friendship formation.

We are considerably more likely to spend time with people who are similar to us, of course. Over the past decade, anthropologist Robin Dunbar at the University of Oxford has identified seven “pillars of friendship” that seem to undergird the most meaningful connections. They are: having the same language or dialect, growing up in the same location, having the same educational and career experiences, having the same hobbies and interests, having the same world view, having the same sense of humour and having the same music taste.

We will share just one or two of these pillars with the 150 or so people that we loosely define as friends rather than acquaintances, but six or seven with our five or so closest allies, he writes in his book Friends: Understanding the power of our most important relationships.

Surprisingly, similarities between friends even stretch to their neural activity. In 2018, Carolyn Parkinson at the University of California, Los Angeles, asked university students to watch a series of videos while they lay in an fMRI scanner. She found that she could predict who was friends with whom based on the similarity of their brains’ reactions to the clips they were watching. The closer they were to each other, the more likely it was that the same regions would respond at the same time.

As I describe in my book, The Laws of Connection, Parkinson’s work chimes with the theory that having a “shared reality” – a common way of viewing the world – is the basis of any strong relationship. “These are people who are paying attention to the same things as us, having similar emotional reactions to what they’re seeing, and so on,” she says. “Such people can be easier to predict and understand when we’re interacting with them – making conversations flow more easily, feel less taxing, and minimising misunderstandings.”

Can we experience that connection remotely? Hall thinks so. “Phone calls and video chats with the people that we love are probably as valuable as face-to-face communication,” he says. “And creating routine opportunities to communicate through the phone or video chat sustains and nourishes relationships.”