Back in 1991, the sociologist Scott Feld made a surprising discovery while studying the properties of social networks. Feld calculated the average number of friends that a person in the network has and compared this to the average number of friends that these friends had.
Against all expectations it turned out that the second number is always bigger than the first. Or in other words, your friends have more friends than you do.
Researchers have since observed the so-called friendship paradox in a wide variety of situations. On Facebook, your friends will have more friends than you have. On Twitter, your followers will have more followers than you do. And in real life, your sexual partners will have had more partners than you’ve had. At least, on average.
Network scientists have long known that this paradoxical effect is the result of the topology of networks—how they are connected together. That’s why similar networks share the same paradoxical properties.
But are your friends also happier than you are, or richer, or just better? That’s not so clear because happiness and wealth are not directly represented in the topology of a friendship network. So an interesting question is how far the paradox will go.