The small world experiment was comprised of several experiments conducted in the ’60s by the social psychologist Stanley Milgram and other researchers. The project examined the average path length for social networks of people in the United States. The research suggested that human society is a small world type network characterised by short path lengths.

To be more precise, according to the idea of six degrees of separation, everyone is on average approximately six steps away from any other person on Earth. Researchers at Facebook and the University of Milan reckon that the degrees of separation between any two people in the world have now been reduced to 4.7. The new research is based on an analysis of the friend networks of 721m people who use the social network regularly.

Another research project has shown that for 84% of users the mean number of friends of friends is always greater than ones own number of friends. Why? Scott Feld wrote about this phenomenon in his 1991 paper Why Your Friends Have More Friends than You Do. This is a classic paradox regarding social networks. The same phenomenon dictates that college students typically find that their classes are larger than the average class size and that an airplane will be more crowded than the average occupancy. The explanation is that if people, classes and flights are popular, you are much more likely to choose them.

The researchers also found that while Facebook makes it easier to connect with people anywhere on the planet, a user’s friends are most likely to be of a similar age and origin. Looking only at links between people within the same country, the researchers concluded that folk are separated from one another by an average of just three connections. We can say that it is still a very small world and becoming smaller all the time!