Ghosting/Unsubscribing, concept (Photo illustration by Salon/Getty Images)

Rachel Jones has unsubscribed. I stared at the computer screen—looking at the list of people who had opted out from my author newsletter. I get it. People are busy and their inboxes overflow. But this friend I’m calling Rachel? She was someone I had known for 35 years. We had lived together once. She was my first fan. When we were young, the plan was that she would be the “fabulous friend” at my book parties. Now she was telling me she was “no longer interested.”

I was deeply hurt. I believe friends ought to show up for each other and that one pretty painless way of showing up is leaving your name on a mailing list.  Except Rachel and I hadn’t been as close in recent years, and our connection already felt fragile. I suspected something I’d written had pissed her off. I got up the courage to write to her. This feels like the end, I said. You unsubscribed from me.

A few nights later, by phone, we talked about what had just happened, and about something that happened ten years ago. Back then, we went out to dinner and ended up in an uncomfortable argument. It was indirectly about politics. I thought she was cynical. I think she thought I was naïve. Sitting there, I could almost see the distance opening up between us.  Afterwards, I was upset. We saw less of each other—a trend led by me. Now, a decade later, we had been inching closer together again, but she said, “you unsubscribed from me first.” She was right. I had.

The pain of ending a friendship is as old as friendship itself. Aristotle addressed it in the “Nicomachean Ethics.” Until recently, we haven’t had a vocabulary to describe the phenomenon the way we do for more institutionalized relationships (See: separation, divorce, estrangement). Social media solved that problem. People ghost us. They unfollow and unfriend. They unsubscribe. This new language takes a hammer to the subtler side of human interaction. On the other hand, naming something gives it standing. And these new words do capture some of the pain of cutting long-standing bonds. They describe my passive-aggressive approach as well as Rachel’s more literal opting out. But it is also lazy language that cheapens and oversimplifies what is usually complex. The unraveling of a friendship—or the difficulty of knitting one back together when it frays—deserves more respect.

I have spent the last five years reporting on the emerging science of friendship. Much of what I learned is helping me navigate the rockier shoals of relationships. It’s why I bothered to send Rachel that email expressing my hurt, and why (I think) we both agreed to talk. We didn’t want to leave it at unsubscribing. Of course, some friendships just fade away. We might or might not regret their loss, but we go on pretty much as normal. The ones we grieve are the ones that once mattered most—often the old friends who share some of our history, like Rachel. The ones we used to talk with into the night, who picked up the pieces when our hearts were broken, who loved the same band with teenage devotion. Yet ending a relationship that no longer serves one or both of you is a natural and even healthy part of friendship.

So how do you decide? How do you know when a friendship has run its course? And how do you handle such a situation with grace rather than ghosting? You can start by considering the following definition of friendship. At a minimum, a good friendship requires three things. The first is that it be long-lasting. To be friends, individuals have to have put in some time together, creating a relationship that is stable and reliable. Friendships must also be positive. They must make both participants feel good. And finally, a friendship requires cooperation and reciprocity. There must be give and take and willingness to help, especially in times of crisis, flowing back and forth.

One of these elements without the others leads to a relationship that isn’t serving one or both of the individuals involved. Time alone is not enough. That’s evident in the many people we work with and never befriend. Even if you wanted to, there simply isn’t time to be friends with everyone—not to the same degree, anyway. It’s also possible to have a long, shared history with someone, but to find being together draining. And a relationship that is lopsided—all take and no give on one side—will not stand the test of time.

Friendships are also more fluid over the long haul than we sometimes imagine. In spite of the hours that have to be invested to make and maintain a close friendship, life is long (if we’re lucky). Each of us needs a core group of people to count on and consider “friends” in the best sense of the word. Most of us have somewhere between two and six intimates in that inner circle, a group that is often split between family and friends. But the population of that inner circle changes as the circumstances of our lives change. We switch jobs or move across the country or start hanging out mostly with the parents of our children’s friends. Some relationships can withstand distance, and some cannot. It’s natural that some of those relationships will fall away.

What matters most is the quality of the bonds we have. It turns out that friendship and social integration on the one hand, and loneliness or social isolation on the other, directly impact our health in myriad ways including cardiovascular functioning, immune functioning, cognitive health, mental health, stress responses and even the rate at which our cells age. Socially connected people live longer, while social isolation is as risky for your health as smoking. Which friendships have the power to deliver health benefits? First and foremost, those that meet the definition above—that are reliable, positive and reciprocal.

Some of this probably seems obvious. Positive, happy relationships are good for you. Toxic relationships are bad, and should be shed, forthwith. But what’s interesting are ambivalent relationships—the kind with some good and some bad in them, like that friend from work who got you through the last deadline but demands attention on an hourly basis. According to one researcher’s count, ambivalent relationships make up nearly half of our social lives. It turns out that the good does not outweigh the bad in such cases, at least not where health is concerned. Ambivalent relationships are bad for our biology. That means that faced with a mixed-bag relationship, we have a few options. We can end the friendship, deprioritize it (shuffle the social furniture, in other words), or we can work to make the relationship better.

Rachel and I chose to work on it. The Newsletter Incident got us talking about our relationship in a new and deeper way. There wasn’t much to lose at that point by being honest. As a result, we broke through the veneer of politeness that had come to dominate our interactions and we uncovered misunderstandings and hurt feelings on both sides. We also realized we weren’t quite ready to give up yet. Our shared history felt worth saving. One of the things that had brought us back together in recent years, for instance, was that I started stopping off to see her when I visited my mother, who suffers from severe dementia. Rachel’s mother is ailing, too. Because we had known each other so long, we each knew each other’s parents well, and it was a comfort to reminisce together.

This new version of our friendship is still fragile, but it has the necessary ingredients. Having met so young, we have had time on our side for decades now, but lately our time together feels fully positive again (we laugh more), and there’s mutual support, too. You could say we are renewing our subscriptions to each other. We are refriending. I hope that word catches on.