In what might be one of the most socially anxious scientific studies ever, researchers have shed new light on who gets unfriended on Facebook - and why.
Two new reports from the University of Colorado Denver looked at the type of person who most people dislike - literally - on Facebook, and how they responded emotionally to the snub.
The study found that the most likely person to be unfriended is a school acquaintance you once knew, but never see in person.
Oh, and school friends who turn out to be racists, Fascists or otherwise politically, um, 'committed'.
"The most common reason for unfriending someone from high school is that the person posted polarising comments often about religion or politics," said Christopher Sibona, a doctoral student in the Computer Science and Information Systems program at the CU Denver Business School.
"The other big reason for unfriending was frequent, uninteresting posts."
The study of 1,077 people also found that it is actions "in the real world" rather than online which get people unfriended most often.
"We found that people often unfriend co-workers for their actions in the real world rather than anything they post on Facebook," Sibona said.
The second part of the study was perhaps less interesting - it looked at the usual response to being unfriended, which unsurprisingly ranged from surprise to sadness.
"You may be more bothered and saddened if your best friend unfriends you," Sibona said.
Well, yes.