It’s an odd metaphor, but the behaviours described in terms of internet communities are definitely something I’ve witnessed in 25 years of being online.

(This post is from 2017 but popped up on Hacker News recently.)

Otters

There’s a pattern that inevitably emerges, something like this:
  1. Community forms based off of a common interest, personality, value set, etc. We’ll describe “people who strongly share the interest/personality/value” as Possums: people who like a specific culture. These people have nothing against anybody, they just only feel a strong sense of community from really particular sorts of people, and tend to actively seek out and form niche or cultivated communities. To them, “friendly and welcoming” community is insufficient to give them a sense of belonging, so they have to actively work to create it. Possums tend to (but not always) be the originators of communities.

  2. This community becomes successful and fun

  3. Community starts attracting Otters: People who like most cultures. They can find a way to get along with anybody, they don’t have specific standards, they are widely tolerant. They’re mostly ok with whatever sort of community comes their way, as long as it’s friendly and welcoming. These Otters see the Possum community and happily enter, delighted to find all these fine lovely folk and their interesting subculture.(e.g., in a christian chatroom, otters would be atheists who want to discuss religion; in a rationality chatroom, it would be members who don’t practice rationality but like talking with rationalists)

  4. Community grows to have more and more Otters, as they invite their friends. Communities tend to acquire Otters faster than Possums, because the selectivity of Possums means that only a few of them will gravitate towards the culture, while nearly any Otter will like it. Gradually the community grows diluted until some Otters start entering who don’t share the Possum goals even a little bit – or even start inviting Possum friends with rival goals. (e.g., members who actively dislike rationality practices in the rationality server).

  5. Possums realize the community culture is not what it used to be and not what they wanted, so they try to moderate. The mods might just kick and ban those farthest from community culture, but more frequently they’ll try to dampen the blow and subsequent outrage by using a constitution, laws, and removal process, usually involving voting and way too much discussion.

  6. The Otters like each other, and kicking an Otter makes all of the other Otters members really unhappy. There are long debates about whether or not what the Possum moderator did was the Right Thing and whether the laws or constitution are working correctly or whether they should split off and form their own chat room

  7. The new chat room is formed, usually by Otters. Some of the members join both chats, but the majority are split, as the aforementioned debates generated a lot of hostility

  8. Rinse and repeat—

Source: Internet communities: Otters vs. Possums | knowingless