It could also be something structural about how the "friendship graph" looks. The mean number of friendships isn't the median or typically experienced number of friendships, and if friendship relationship distributions follow some kind of power law, a change in the power-law exponent could make those diverge.
I am wondering the same thing. It's interesting that they didn't report at all on the median and only the average. Also find the timing interesting, as I can't help but suspect that both the justification and incentive for self-reporting a higher number of friends materially changed for some people in the early days of social media. They didn't seem to acknowledge this at all.
The model they built that draws a causal relationship between graph density and polarization is interesting, but these gaps leave me skeptical.
There are just so many other reasons I can see for polarization.
1. Late-stage of civilizational monetary cycle (bretton woods - petrodollar) -> historically leads to polarization
2. Dramatic increase in access to information / wide range of things to know and care about
3. Attention economy (novel upsetting news is best at getting attention, not nuance, not truth)
4. Habits of instant gratification diminishes patience for nuance
5. Maybe foreign state interference/bias towards polarization to destabilize rivals?
6. Several more maybe??
So I buy the graph density correlation, and I'm curious about contributing to causation, but I'm extremely skeptical that it's the primary or sole cause.
I think you left out the biggest one (though I suppose #3 indirectly hits on this). Social media, and increasingly even online media in general, tends to heavily misrepresent 'the other side.' In the past relationships were formed primarily in person so you actually got see what 'the other side' was like. Now a days people instead depend on completely inaccurate stereotypes that are far more like cartoon caricatures than real people. See: the perception gap. [1]
So people simply don't understand 'the other side', but ironically think they do - which is a rather toxic combination. For instance the more news somebody follows, the less accurate their assessments of 'the other side.'
I agree completely, though I continually wonder why. Is it by specific design? By economic incentive? Is it because novel threats attract attention, and having a need to be validated continually satisfied maintains attention?
I can't help but wonder if the polarization in the media is deliberate (e.g. foreign state sewing division) or accidental (second order consequence of attention economy) or organic (the claims of the paper, and/or other psychological effects of anonymity, etc.) or maybe all of the above?
It's a natural consequence of a highly-connected communication graph. People with extreme political views talk about politics a lot, so casual political conversations are naturally going to disproportionately represent the extremes. Similarly, when people more-or-less agree, they tend to discuss politics less (because there's only so much preaching the choir that people can stand). Most meatspace communication graphs happen between people who tend to have similar world views, but online, you've got neonazis and anarchists replying to the same reddit threads. The combination of the above two factors means that by far the most political views you'll end up seeing are 1) your own, followed by 2) extreme versions of your opposition's views.
Just look at any form of social media. Many, if not most, people seem to seek out and enjoy drama. A straight forward representation of some event is usually going to get orders of magnitude less "engagement" than a excessively hyperbolized and sensationalized representation of it, even if the latter may often play a bit fast and loose with the facts to further magnify the dramatic effect of it all.
And then with every sort of algorithm and feedback mechanism (e.g. upvotes, likes, etc) based on maximizing "engagement" you then get this stuff spreading everywhere and even further drowning out any sort of rational discussion. So people who regularly follow it are going to be living in some sort of alt-reality all the while convinced that they are the most informed about the latest happenings in the world.
When was that past? People used to hate you for being from a different village.
Polarization could instead be because there are fundamental differences in how people see the world and what is right. And now that we've tangled ourselves through all the wars imaginable to dispel the old division lines, this is what we're left with. This is what we have, now that information has become available for the masses; the real differences which split people. Not based on phony dividers of the past.
Polarization also means that if you disagree with the ideology of your family or of your village, you have millions of friends on a national or international level who think like you, instead of being ostracized for life.
It seems insane to try to connect a twenty year shift in one global variable to one causal factor. This approach is why the social sciences continue to struggle to create understanding. It is all they can afford to do, though.
That said, 3) I think possibly best explains both: the increase in average number of friends due to influencer dynamics skewing the distribution, and the increase in polarization due to the tactics in social media.
However there seems to be no chance it is a durable or reproducible link, as it depends on the novelty of polarization techniques which wear over time and become known and integrated in education, reducing their effectiveness
