Least any of us think that Social Network Analysis is something new, please take the time to read this wonderful, albeit personal, history of the field.   Edward O. Laumann, of the University of Chicago, has been swimming in these waters for more than 40 years.  His address to the International Network of Social Network Analysis, 26th Annual Sunbelt Conference in Vancouver, Canada, April 2006, tells much about how we have arrived at the current level of SNA

See “A 45-Year Retrospective of Doing Networks”
http://www.insna.org/Connections-Web/Volume27-1/8.Laumann.pdf