The Friendship Paradox

Pick any person you know. Not your closest friend — someone in the middle of your social circle. Now ask a simple question: who has more friends, you or them? Most people answer "me" or "about the same." That feels right. You picked someone average, you consider yourself average, so the numbers should be roughly equal. Here is what the math says: on average, your friends have more friends than you do. Not because you are unpopular. Not because you chose poorly. This is true for almost everyone in almost every network that has ever been measured. To see why, you need to build a small world. Five people. Call them A, B, C, D, and E. Give them friendships — and make the network lopsided the way real networks always are. A knows B and C. B knows A, C, D, and E. C knows A and B. D knows B. E knows B. Count each person's friends. A has two. B has four. C has two. D has one. E has one.