The original "Dark Forest hypothesis" is the idea that alien civilizations are silent not because they're not out there; and not because they wouldn't love to meet us and form positive-sum interactions; but rather because they've all concluded — from evidence or pure logic — that there are likely to be scary things "out there" listening; and that, by trying to draw attention to themselves to make friends, they would also draw the attention of these scary predators.

Modern social networks have the "dark forest problem" insofar as your mom, or your boss — or the HR departments of random companies you might in the future apply to work for — might be able to join, follow you, and see your posts. In this analogy, your mom/boss/bigcorp-HR are the predators lurking in the Dark Forest. Knowing they're there makes you go silent, refusing to "make yourself known" / "make yourself vulnerable" in any way these predators might potentially latch onto.

The analogy does break down a bit, because unlike alien civilizations in the cosmic void, there are signals we as individuals can send out on a social network that "make us known" at least somewhat but don't "make us vulnerable." These are the "performative, groomed" posts you see shared on Facebook, posted on public Instagram accounts, blogged on LinkedIn, etc. (I suppose a more-precise name, that incorporates this consideration, would be the "chaperone problem" — but that's less evocative.)

Social networks are good and fun and easy — possibly even a net positive for mental health — when they either inherently or coincidentally avoid becoming a dark forest.

In real-world terms:

• Interest-based activity groups (think "knitting circle" or "D&D group"), and community [not professional] sports leagues, are great social networks.

• Conventions, youth summer camps, and adult workshops [think "pottery class"] are all also great — though ephemeral — social networks.

• Group therapy sessions are good social networks.

• A high school is — perhaps shockingly — a decent social network. (It has failure modes, yes, but it almost never fails in the dark-forest sense of "nobody ends up making any friends because everyone's too scared to talk.") And a college is a slightly better social network — not as good at producing friendships, but the friendships are more likely to last beyond the years you spend there.

Good online examples of social networks are mostly older: the single-interest phpBB forums; early online games, before ELO-based matchmaking; and, yeah, old Facebook. (And MySpace, too.)

• I think Tumblr is probably the oldest major "modern" social network that hasn't yet succumbed to the dark forest problem. Not sure why. (Maybe it's just never attracted the right sort of celebrity posters to give moms or bosses any reason to join, I guess. Or maybe the fact that Tumblr posts (used to?) have public web URLs, meant that viral-meme Tumblr posts could simply be linked to, without that then forcing visitors to join the platform? Or maybe the fact that Tumblr lets users have multiple blogs each — sort of like how YouTube accounts can have multiple YouTube channels each; so Tumblr users can have one "clean" blog tied to their identity, that they can show people, and then other blogs that they post more outré — yet meaningful and vulnerable — stuff to. But without these being true "alts", as account DMs can still only originate from the main-blog identity.)

• BlueSky has also avoided the dark forest problem for now, but that's likely temporary; there's nothing in its design that makes it any less "for everybody" + "for public performance" than Twitter is/was.

Everything else is either a ghost town save for its performative stage (Facebook, Twitter, LinkedIn, even HN somewhat); or it's an archipelago of out-of-band-formed groups of mutuals who are otherwise private and undiscoverable through the platform itself (Instagram, all group-chat apps); or it's not a "social network" at all, in that there is an expectation of anonymity / creating alt accounts / being able to (Reddit, 4chan, modern online games.)

It'd be interesting to design a social network from the ground up with the goal of making it inherently impossible for the network to devolve into a dark forest.

This is correct. There is no understanding, there aren't even concepts. It's just math, it's what we've been doing with words in computers for decades, just faster and faster. They're super useful in some areas, but they're not smart, they don't think.