A statistical phenomenon is provided. Your job is to figure out an explanation that ties in with bias.

-Your friends are (probably) more popular than you are. Sociologists have conducted surveys in which they select random people and ask for a list of the people they know, and then they contact a sample of the friends and repeat the survey. The people sampled at the second stage have, on average, many more friends than do the people in the original sample. This suggests that, on average, your friends are more popular than you are.