In this post I will argue that "imageboard culture" is latent in the technology, such that a new chan populated entirely by imageboard virgins would quickly resemble 4chan.
"Anonymity" is the trivial feature that everyone brings up, but I think even more relevant is the lack of quantitative feedback on posts, except for (You)s. Most sites have explicitly positive feedback options and sometimes negative ones. Thus, the primal instinct to "make number go up" can be satisfied through like or upvote optimization. And a downvote optimizer has a rough time since their posts are likely to be algorithmically obscured. The infamous Reddit circlejerk culture appears. But on imageboards, all optimizers are (You) optimizers. And the ordering of comments never changes, so the sentiment of the (You)s is irrelevant.
A "fit" channer is one who can acquire the most (You)s with the least effort: easy dopamine encourages these posters to stick around. I'd argue that the most cost-effective way to gather (You)s is to identify new threads with high potential for replies, and leave an irresistible bait as one of the first replies. (The last replies are ephemeral, but anyone who opens the thread will always see your bait.) This strategy is now explicitly recognized in the form of the "second post best post" meme. To be able to utilize this strategy, you need to be quick-witted and you need a honed meta-contrarian mindset. A good bait is funny and appears to be sincere opposition to the OP or to the predicted views of later repliers. Posters with these traits are selected for, by their own biological reward system interfacing with (You) count, and the infamous "smart people pretending to be idiots while defiling sacred values" culture emerges.
There are other strategies for (You) optimization, such as GETs. GETs are unique to imageboards and therefore create another unique aspect of imageboard culture.
Another strategy is creating good content like funny memes or effortposts. But this strategy works even better on modern dopamine-efficient social networks like Twitter, which additionally tend to give popular content more exposure for a snowball effect. 4chan has no comparative advantage here, so it's no longer the meme center of the Internet, as much as it likes to pretend otherwise.
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