This mirrors my current thinking. Each individual naturally filters out information that they consider weird, the less they know the person that they are readi

This mirrors my current thinking. Each individual naturally filters out information that they consider weird, the less they know the person that they are reading, the farther it is from their viewpoint, the more that idea will be passed over. Each community is made up of the average of the opinions of its members, and we can collectively track this through the Overton window. The more people that don't know each-other in a community, the less their weirdness budgets are, therefore the slower the community is able to change its mind. This is where Dunbar's Number comes in, eventually you reach a point where the Overton window metastasizes and two factions in that community break apart. So what we really need to be asking is... 1. Dunbar's number suggests that as a community gets larger, it should naturally split, why don't digital communities do this? One obvious conclusion is that the internet sites that we are building them on top of do not allow the split. The website is owned by the web owner, and they want all communication on it, and they don't have any sharding built in, so we can't split. But even when we build sites like Reddit that are inherently built of many communities and make it extremely easy to create new communities, we still see concentration of communities. So it is dismissive just to say it is the owners fault. It must somehow be that, because digital is so effective, the economies of scale within the digital space grows and even with the worsening of communication the community gets stronger with each member. That is, opinions within the websites Overton window have such good quality, that it doesn't matter that all discussion outside the window is ignored. And there are mostly more people entering than there are leaving, so it works out until it doesn't. And thus as you say, the only option we have to reach beyond our local maximums is to split the communities soon after we reach something close to Dunbar's Number. Does that mean each community would just be 150 people? Does that mean each person could only be a community of 150 people local to them? No. You can have a community of the top community members, and that 150 community would have it's own Dunbar's Number. In fact, this is mostly what the House of Representatives and the Senate are, or was before 1920.