I love to post online. This is a post, I have made many posts of varying quality on all sorts of platforms. I can’t get enough of posting.

But my true love is lurking — observing strangers online but never interacting with them. Scrolling deep back into some random person’s Instagram page, reading tweets from people I’ll never meet, and my new nightly ritual of watching TikTok — where not a single person I know IRL posts.

I’m not worried about how much time I spend on my phone, to be honest, because I find online to be an oasis of mirth compared to the physical world. I have KonMari-ed my feeds so that Twitter brings me nothing but joy, Groups on Facebook bring me interesting discussion with likeminded people, and TikTok shows me teenagers being funny. I may be addicted to my phone, but I’m a highly functional addict. I’m fine! I love it!

But one night, deep into a TikTok scrolling session, it occurred to me: What is it doing to my brain? Specifically, what does it do when I sit in my bedroom and see into the bedrooms of thousands of people I’d never meet in real life? Is this bad for me? Is my brain evolutionarily equipped to handle seeing this many strangers???

Most of the studies about how social media affects our brains focus on teenagers and young people, which I am no longer. And that research suggests it’s not, uh, great. Sort of. It’s complicated. Heavy internet use for young people tends to have side effects that aren’t great, like decreased real-life social activity, sleep, and physical activity.

Other areas of research focus on mental health: how Instagram or Snapchat create feelings of FOMO, or how influencer culture affects girls’ body images. Scientists have studied brain function in heavy gamers and found a connection to decreased gray matter in certain parts of the brain. Lucky for me, I am neither a gamer nor a teen, so neither of these applies.

In fact, I’m not even what researchers consider a digital native — I was a teen in the late ’90s, and though I had access to the internet, I wasn’t much of a heavy user until college and my twenties, making me a “digital immigrant.” Essentially, my brain has been preserved because I graduated high school when I had to call my friends on their family landline and ask their parents if they were home. I imagine my late-in-life lurking affects my brain the way someone picking up smoking late in life with pink, healthy lungs might: not so bad!

A scientific theory called Dunbar’s number posits that the human brain can only maintain a social circle of 150 friends. Your close friend group is much smaller, and you can recognize the names and faces of far more (around 1,500 people), but 150 is the limit for people who you can actually keep track of.

Robin Dunbar, who came up with the theory in the early ’90s based on research on primate brain size, recently clarified that the advent of the internet hasn’t actually changed that 150 number. Sure, I might recognize the names and faces of my 1,183 Facebook friends, but that doesn’t mean that I am actively keeping up with their lives or communicating directly with them regularly.

It’s true that being active on social media helps you remember more names and faces of acquaintances than you’d be able to without Facebook or Instagram. Research has shown this. But since all these weak online connections won’t really cross into our circle of 150, it’s unclear what the actual effect of this new activity is on our brains.

But this is all concerned with maintaining friendships and relationships online — not lurking. I am not trying to maintain a friendship with Jake Paul, although somehow my brain has retained a short list of whom he is feuding with at any given moment (currently: Zayn Malik and Gigi Hadid). Even that kind of celebrity gossip uses a different cognitive function.

To passively scroll past thousands of strangers is very different than the kind of social relationship that I passively maintain on social networks with what are acquaintances at best.

My brain has to do a fair amount of work when I’m looking at my friends’ posts. I might actually react — like a photo or tweet, maybe reply to an Instagram story over DM. There are pieces of information that I choose to retain: Someone went on an interesting vacation, someone has a new haircut or got engaged, details I want to remember and maybe talk about with them later.

But with strangers, I’m free. I need to retain nothing, I treat their posts like a visitor to our national parks: leaving no trace, taking nothing but the occasional screenshot.

What exactly is the neurological effect of viewing so many strangers? I asked Joseph Firth, a senior research fellow with the NICM Health Research Institute at Western Sydney University, who was one of the authors of a research paper, “The ‘online brain’: how the Internet may be changing our cognition.” Firth and his colleagues were more concerned with other areas — how the internet affects mental health in young people, or how the ease of online search might benefit memory for older adults.

Firth wasn’t too worried about the effects of viewing too many strangers. “I think there is no evidence that seeing online strangers would be any different to the vast amounts of ‘strangers’ we see day to day in real life, in transit, at malls, etc, etc.,” Firth said. He pointed out that plenty of people see tons of strangers IRL as part of their profession — a checkout clerk at a busy store or someone at a customer service call center. “And so it seems the human brain is perfectly equipped to manage constantly seeing/processing strangers, online or in real life.”

Of course, anyone who has worked a retail or service industry job would probably argue that there’s an incredible emotional and mental toll from dealing with so many people on a daily basis. Actually talking to new people all day — especially in a customer–worker relationship where there are unpleasant confrontations — is exhausting, even for extroverts.

The idea that seeing so many strangers on busy city streets isn’t our natural state isn’t new at all. At the turn of the century, German sociologist Georg Simmel fretted about the way that metropolitan life, with all its crowds and focus on money, was changing our interior lives. To him, small-town life was pure and emotional, while city dwellers became calculating and intellectually detached, resulting in the dreaded “blasé attitude.” This doesn’t seem totally unfamiliar to the more modern fretting over people who are Extremely Online being irony-poisoned or status-conscious influencers acting out of calculated motivations on what type of outfit or photo will get the best engagement with their audiences.

Fear over the latest new technology poisoning our delicate brains isn’t new either; decades ago, people thought television was ruining the minds of our youth, and before that, radio, and before that, reading novels was a controversial pastime. At one point, the written word was going to destroy civilization.

Joanne McNeil’s recent book Lurking addresses an age-old complaint about why people post to Twitter or Instagram: “Who cares what you had for breakfast?” This implies that people are on there simply to post about themselves. But the reality is that the real value of social media is being able to see what other people had for breakfast. It isn’t the narcissism, it’s voyeurism. It’s nice to get likes and hearts from your followers, but the central experience is being able to view others.

Lurking is, in fact, the dominant mode of using the internet. You’re likely to spend far more time looking at Instagram than you are posting to it, even if you’re a Kardashian. Even if posting about yourself is motivated by a need for positive feedback, the internet exists always as a place to view others and position yourself next to them, whether this is the other kids in your high school or complete strangers.

There’s a dark flip side to my joy in watching teens do harmless viral dances. There are plenty of very bad, hateful, awful things I’ve observed while lurking — and there is evidence that regular exposure to this kind of bad stuff is bad for the brain. McNeil wrote, “At its worst and at its best, the internet extracts humanity from users and serves it back to other users.”

Firth did say there was one possible upside: “The only place where I could see online platforms being hugely beneficial for socialising would be in cases of individuals who are housebound, or otherwise isolated, to continue engaging with their friends/associates through the digital world.” I’m not housebound, but due to my extremely advanced old age and family obligations, I don’t get out to socialize as much as I used to. As my social life slowed down in my thirties, I’ve found online socializing more and more useful (of course, this timing coincides with rise of social platforms over the last 10 years, so, chicken and egg). As a parent, I’ve found online communities of strangers invaluable, and I suspect fellow tech writers who have lamented their own reliance on their phones have not frantically asked about mastitis to a Facebook group before.

Selfishly, I am relieved to hear from a scientist that my lurking is not ruining my pristine and giant brain. This is fully the outcome I was hoping for, and I’m thrilled to share the good news with you all. If only the verdict on some of my other vices could shake out this way. ●