When it comes to susceptibility to influence on social media, “It’s not just about who you are—it’s about where you are in a network, and who you’re connected to,” said Luca Luceri, a lead scientist at USC’s Information Sciences Institute (ISI). A new study by Luceri and his team finds that the likelihood someone will be influenced online isn’t spread evenly across a social platform. Instead, it clusters.

They call this the Susceptibility Paradox; it’s a pattern in which users’ friends are, on average, more influenceable than the users themselves. And it may help explain how behaviors, trends, and ideas catch on—and why some corners of the internet are more vulnerable to influence than others.