Facebook certainly did at least one thing: it gave users connections to more individuals than humans have ever had before.

The giants of the social web—Facebook and its subsidiary Instagram; Google and its subsidiary YouTube; and, to a lesser extent, Twitter—have achieved success by being dogmatically value-neutral in their pursuit of what I’ll call megascale. Somewhere along the way, Facebook decided that it needed not just a very large user base, but a tremendous one, unprecedented in size. That decision set Facebook on a path to escape velocity, to a tipping point where it can harm society just by existing…

The on-again, off-again Facebook executive Chris Cox once talked about the “magic number” for start-ups, and how after a company surpasses 150 employees, things go sideways. “I’ve talked to so many start-up CEOs that after they pass this number, weird stuff starts to happen,” he said at a conference in 2016. This idea comes from the anthropologist Robin Dunbar, who argued that 148 is the maximum number of stable social connections a person can maintain. If we were to apply that same logic to the stability of a social platform, what number would we find?

“I think the sweet spot is 20 to 20,000 people,” the writer and internet scholar Ethan Zuckerman, who has spent much of his adult life thinking about how to build a better web, told me. “It’s hard to have any degree of real connectivity after that.”

In other words, if the Dunbar number for running a company or maintaining a cohesive social life is 150 people; the magic number for a functional social platform is maybe 20,000 people. Facebook now has 2.7 billion monthly users.

For much of human history, social interaction included only a relatively small number of people. The interactions occurred in a small geographic space. Some exchange in terms of news, trade, and people happened but not on the fast, global scale of which we are accustomed to today.

Facebook and other social media companies allow users access to thousands, if not millions, of users. Even as users have some choice about these connections, the possibilities are unprecedented. If humans found it daunting in the nineteenth century to encounter growing big cities (and early sociologists looked to explain the massive social changes connected to urban society and interaction), how do we comprehend all of the possible interactions today?

Some research suggests that even if users could access all these connections, they do not necessarily do so. Do Facebook users or Twitter users or other social media users regularly interact with people they do not know or do they primarily stick to people they know and/or known sources? Actually stepping across boundaries may be easier in the social media realm but they are still boundaries.

Does this suggest that humans cannot interact with global communities? Or, is this interaction not possible on an individual level and instead needs to be mediated through institutions, such as mass media or governments or corporations? Facebook’s experiences may just be helping people think about how to broaden connections without overwhelming those involved.