Networks are endlessly interesting. They shape the world around us like almost nothing else, yet we spend very little time thinking about them or recognizing the non-obvious ways effects they have on our world. Because we tend to think in bell curves, we get tricked by networks pretty often. For instance, we’ve all had the experience of feeling like everyone is talking about something when it turns out to be pretty self-contained to your little group. Well, some folks at USC have spent some time looking into just how networks create that illusion, which they call the majority illusion:
The majority illusion occurs when the most popular nodes are colored. Because these link to the greatest number of other nodes, they skew the view from the ground, as it were. That’s why this illusion is so closely linked to the friendship paradox.
Interestingly, the majority illusion can even show up when a node isn’t globally popular:
That might seem harmless when it comes to memes on Reddit or videos on YouTube. But it can have more insidious effects too. “Under some conditions, even a minority opinion can appear to be extremely popular locally,” say Lerman and co. That might explain how extreme views can sometimes spread so easily.
As with most things related to how ideas spread throughout networks, the more popular something is seems to be the only reliable indicator to how popular it will become.