Friendship Paradox

Originally documented by a sociologist named Scott Feld in 1991, the Friendship Paradox says that our friends will tend to have more friends than we do, and that this is true for pretty much everyone.

This is paradoxical because some people have many friends, some have fewer, and some have a roughly average number of friends, and it would seem that just as choosing a random person from a group would give you a roughly equal chance of selecting someone from anywhere on that number-of-friendships spectrum, the same would be true of randomly choosing someone from the friend group of that initial, randomly selected person.

In reality, though, people with more friends will be more likely to show up in more peoples’ friend groups, so the numbers are skewed in their favor if you go down a level.

The counterintuitive result of that skewing is that the sample you’re working from when you look at a random person’s friend group will be different from the broader sample from which that first random person was selected, because there will be more people with a lot of friends represented in more peoples’ friend groups, by definition.