With Friends Like These
On average your friends tend to have more friends than you do, for reasons described as the Friendship Paradox.
As briefly mentioned by our guest speaker, a case of sampling bias occurs when thinking about one’s group of friends. The more friends someone has, the more likely it is that person will be included in our own friend group. In other words, people with more friends will be more likely to be friends with you than those with less. This is true for nigh everyone except those at the very top of the friend-having ranks. It would be interesting to see how the model changes at this level.
The mathematical rule applies other situations with similar nodal structures as well. Examples include twitter followings, citation references, sexual partnerships and the spread of disease.
And it doesn’t apply only to one’s number of friends, but also to related measures such as happiness and wealth, as the article explains.