friendship paradox

The analysis of the friendship paradox implies that the friends of randomly selected individuals are likely to have higher than average centrality.

The friendship paradox is the phenomenon first observed by the sociologist Scott L. Feld in 1991 that most people have fewer friends than their friends have, on average.

They found that using the Friendship paradox to analyze the health of central friends is "an ideal way to predict outbreaks, but detailed information doesn't exist for most groups, and to produce it would be time-consuming and costly."