This research makes a few points that are interesting, relevant, yet slightly counterintuitive. According to this article, by Complexity Science Hub Vienna, the number of close friends people have has increased over the past fifteen years (starting between 2008 and 2010). This coincides with the rise of smart phones and social media. However, political polarization has also increased. According to the article, those consistently expressing liberal views rose from 14% to 31%, while those holding conservative views increased from 6% to 16%. The researchers explain that since most people have more close friends, they are more likely to cut ties with one who has different political beliefs then they do. That means more of us have friend groups that see the world they way we do politically. In other words, there are less ‘bridge friends’ who help expose us to different viewpoints. The end result is less dialogue and more breakdown of our democracy, both of which are becoming enormously dangerous at present.

Another interesting angle has to do with Dunbar’s number, which suggests we can only maintain about 150 meaningful relationships, with roughly 5 close friends in our innermost circle. This research shows we went from 2 close friends to 4-5 around 2008-2010—so we’re actually approaching the upper limit of what Dunbar predicted for our intimate circle.

Thus, it can be said we are not exceeding our cognitive capacity for friendships; we’re just filling it differently. Social media didn’t give us superhuman social abilities. Rather, it made it easier to maintain more connections within our natural limits. But here’s the problem: when you’re at capacity with like-minded friends who are easy to maintain online, there’s no room (or motivation) for the harder work of bridging divides with people who think differently.

In other words, Dunbar’s Law explains why the doubling of close friends leads to polarization: we’ve hit our cognitive ceiling, so we’re now optimizing for similarity and comfort rather than diversity. Our social “budget” is maxed out on echo chambers.