What is the small world theory?

1929, the Hungarian writer F Karinthy first put forward the theory of "small world phenomenon" 1. He believes that any two people on the earth can be connected by a chain with an average of six contacts. Then in the 1960s, Stan-ley Milgram, a professor of social psychology at Harvard University, put forward the idea by designing a chain letter experiment.

This paper introduces the development history of small-world theory. Based on the statistical analysis of "small world" related papers in the full-text database of China journals from 2000 to 2007, this paper probes into the research status and research shortcuts of small world theory, and puts forward the new trends of small world theory research.