I’ve worked remotely for most of my professional life, collaborating exclusively through whatever screens were at hand, and I know a few things about how lonely that can be.

All of us sense that the internet is no cure for loneliness, and research supports our intuition. People who spend more time online are less happy, and some studies suggest this is more than mere correlation. Loneliness, in turn, is an actual hazard to our health, more dangerous than obesity and nearly as lethal as smoking.

But what are we to do when connecting with people online is our only option? With the abrupt arrival of the coronavirus, we’re being told that covering our mouths, washing our hands and avoiding other people is a matter of life or death—if not for ourselves, then possibly for someone we love.

Keeping our distance

A few months ago, the world was a bustling place, and now the fate of the global economy and the lives of millions appear to rest on our willingness to engage in “social distancing.” Suddenly and unexpectedly, working, studying and even relaxing with friends remotely seems, for millions of people the world over, the only option.

It is beyond debate that these remote collaborations may be less fruitful than in-person meetings; the learning less effective than what we absorb in hands-on environments; and the socializing markedly less satisfying than the alchemy of face-to-face connections. Even staunch advocates of remote work such as Jason Fried, author of the book “Remote,” have acknowledged that it is important to occasionally get your team together in person to cement social bonds, build trust and brainstorm.

But why these online-only connections don’t quite cut it remains something of a mystery to social scientists. Sure, it is easy to say that humans evolved for in-person communication, that our uniquely expressive faces, eyes, bodies and vocal cords convey far more information than words on a screen ever could. And all this isn’t only self-evident but backed by a fascinating array of research: Anthropologist Ray Birdwhistell has asserted we are capable of 250,000 different facial expressions. Research by body-language experts Allan and Barbara Pease indicates that 60% to 80% of the impact of someone’s arguments in a negotiation is attributable to body language.

Operating under the assumption that capturing more of this nonverbal communication is always better, psychologists have created a measure of how rich a medium is, which they call “social presence.” Video chat has a high level of social presence, while texting has a low one.

But for anyone who has ever been reassured by a text from a friend, laughed at a colleague’s joke in Slack or had their mind changed by an exchange on social media (the rarest scenario of them all), it is clear that the richness of a medium isn’t the sole determinant of how it makes us feel.

Even a communication with a high level of social presence can’t be depended upon to cure the gnawing hunger for human connection that bares its yellowed fangs when we least expect it. Who among us hasn’t logged into a Skype, Zoom, Google Hangout, WhatsApp or [insert your service of choice here] video call, gazed upon a screen full of other people on their laptops and felt, if only for a moment, that flickering existential dread? “This is how I will die—alone and under less-than-flattering light.”

In an age of remote everything, especially one in which our jailer is a potentially lethal virus, the underlying feeling is that how we choose to live our days is how we will end them: hunched over a screen, pressing “refresh” until the very end.

The interaction factor

If the richness (or lack) of a medium can’t explain why the quest for connection on the internet can be so fruitless, perhaps another, older theory does.

In 1956, sociologists Donald Horton and Richard Wohl coined the phrase “parasocial interaction.” It characterized the emotional ties millions of people had developed with performers and personalities beamed into their homes through the then-new medium of television.

This “intimacy at a distance,” as they described it, was striking because, in all of human history until the invention of the gramophone and radio, hearing a human voice meant someone was present. TV added a visual element, and the logic embedded deep in our fundamentally social brains—I hear a voice and see a face, therefore someone trustworthy is present and I feel safe—kicked in.

The problem was that all these relationships were one-sided. Sitting around the house watching television, parasocializing with our favorite news anchors or sitcom characters, didn’t confer the same benefits as socializing with real people.

For half a century, the nature of broadcast media meant it was only celebrities with whom we could form parasocial relationships. But with the advent of the internet, which grants us the ability to communicate with anyone through a screen, a funny thing has occurred: All relationships, even ones with people who know us and reciprocate our fellow-feeling, gained the potential to become parasocial.

But this parasociality is different than the earlier variety, existing somewhere in the gray area between a completely one-sided relationship and the special something that comes from a truly shared encounter.

Social media makes it easy to hang onto and follow along with “friends” with whom we rarely or never speak. With social media, our primate brains generate the illusion that we are participating in our friends’ lives, just as our parents instinctively felt a closeness to the voices in the little box. Communicating through the internet also necessitates the construction of a digital self, which is by nature incomplete and often false.

The internet also creates a mental equivalence between everything and everyone on a given network, one that erases the boundaries between our interpersonal relationships and parasocial ones. When friends’ tweets, TikToks and Instagram posts are interspersed with content created by professionals we don’t know, selected for us by an automated filter, we perform the mental trick of viewing all of it as the same sort of thing. And if it is all the same, well, suddenly our friends’ awkward, poorly composed, occasionally nonsensical content pales by comparison to, say, cheeky “Star Wars” fan trolling by Mark “Luke Friggin’ Skywalker” Hamill himself.

Then there is that awful word, “content,” a catchall that is equally valid for describing a friend’s post and the advertisement that interrupts it. In its unctuous inclusiveness, the definition of “content” provides yet more evidence that online, all interactions are smeared into one broad stroke of snackable one-sidedness.

The antidote to the slow poison of parasocialization is, of course, socialization. Just like our primate ancestors. Live and in the flesh. And unfortunately, millions of us are about to find out just how long we can survive without it.

Mr. Mims writes The Wall Street Journal’s Keywords column. He can be reached at christopher.mims@wsj.com.