Brian Ball and M. E. J. Newman analyzed friendship data from a high school and junior high, and found a hierarchy similar to the one in Mean Girls.
Here we analyze a large collection of such networks representing friendships among students at US high and junior-high schools and show that the pattern of unreciprocated friendships is far from random. In every network, without exception, we find that there exists a ranking of participants, from low to high, such that almost all unreciprocated friendships consist of a lower-ranked individual claiming friendship with a higher-ranked one.
So someone higher up on the totem poll had more people saying they were friends with him or her, but the popular one didn't necessarily feel the same.
I told my wife this, and her reaction was basically, "Uh, yeah. And?"