After a point, adding more short cuts does not improve network efficiency. Such worlds could be random but they are not. They have a great deal of structure, which is created by short cuts between a few power stations, a few special cells in the nervous system or certain prominent actors who make a lot of movies, Watts said. These short cuts can be identified and measured, which means that they act as a unifying principle for small worlds in general. The finding of what difference a few short cuts can make has radical implications for people, Watts said.
Most people know only their immediate neighbors and friends but a few people are well-connected.
They cross geographic, social and political boundaries and make the world seem smaller. For example, if you knew Secretary of State Madeline Albright, you would be connected to everyone she knows, including kings and queens. But even if you are not her friend, you may be connected to her indirectly. If so, you would be connected to the Queen of England by three degrees of separation . The notion that all people are connected through indirect networks was first studied by the Stanley Milgram, a social psychologist at Harvard University who in 1967 asked people in Nebraska and Kansas to mail a letter to two people in Boston with whom they were not acquainted.