6 Degrees + 1 Game Theory = Social Network Analysis

It took a Beautiful Mind to develop Game Theory. A Footloose actor to popularize 'Six Degrees of Separation.' Now Social Network Analysis has pushed the envelope on both these theories for security purposes. However how does this new form of analysis affect our privacy rights? Will our future innocence or guilt be based on mathematical formulas?


Six Degrees of Separation (also referred to as the "Human Web") refers to the idea that, if a person is one step away from each person they know and two steps away from each person who is known by one of the people they know, then everyone is at most six steps away from any other person on Earth. The concept was first introduced in a play written by John Guare. The game "Six Degrees of Kevin Bacon" was a by-product of the theory, whereby any person can be linked to Kevin Bacon through no more than six connections.

In 2007, Kevin Bacon took the concept one step further by transforming  the game into an official online charitable challenge. Found at sixdegrees.org, Bacon discusses his philanthropic endeavor with Hannah Storm on CBS's Early Show.

John Forbes Nash Jr.is an American mathematician and economist whose works in Game Theory has provided insight into the forces that govern chance and events inside the complex systems of or daily lives. Nash is also the subject of the movie, A Beautiful Mind,a loosely based biopic.

Game theory attempts to mathematically capture behavior in strategic situations, in which an individual's success in making choices depends on the choices of others. While initially developed to analyze competitions in which one individual does better at another's expense (zero sum games), it has been expanded to treat a wide class of interactions. Today,  Game Theory is a sort of an umbrella or 'unified field' theory for the rational side of social science.

A trailer for the 2001 movie A Beautiful Mind gives some insight into the man behind the theory.

According to the Independent, Social Network Analysis in its simplest form is a way to "connect the dots" between different people who either know each other directly or who know someone who knows someone else in a web of contacts. It has been used in social networks like Facebook, LinkedIn and MySpace.

Kathleen Carley of Carnegie Mellon University in Pittsburgh describes social network analysis as that which "analyzes information about who knows who or who talks to whom."

While Facebook is data-mining copious amounts of information on people, their demographics and psychographics, social networking now takes that data and analyzes it mathematically to tell you 'who' the critical people are. And therein lies the essence of social network analysis or what some are calling 'metanetworking.'

How Six Degrees of Separation and Game Theory helped move Social Networking Analysis forward can be understood more clearly by using the example of 9/11. The key moment for social network analysis probably came into play immediately after the September 11th terrorist attacks on the United States. It was then that civilian social network analysts began to investigate the 19 hijackers and their associates using publicly-available information released in the media.

One management consultant, Valdis Krebs, scoured newspaper reports to build up a social network of the 19 terrorists that he could begin to analyse. Within weeks, his network began to create a visual and mathematical picture of the links between the terrorists, with each name becoming a "node" in the net.

September 11 Social Network AnalysisSeptember 11 Social Network Analysis

It soon became obvious to Mr Krebs that one of the key figures was Mohamed Atta, the Mohammed AttaMohammed AttaEgyptian-born ringleader of the group who became a member of alQaeda while studying in Hamburg. Atta's "node" scored highest on all three "centrality metrics" of the social network – measures known as "degrees", "closeness" and "betweenness".

The network also revealed the dense interplay of relationships between a subset of the hijackers who were later known to have formed the terrorist cell that Atta had helped to build up while in Hamburg. "The dense connections of the Hamburg cell are now obvious," Mr Krebs wrote in 2002.

Dr Ian McCullohDr Ian McCullohDr Ian McCulloh, a US Army major at West Point Military Academy in New York, said that he has used social network analysis to work out relationships between the many hundreds of videos of American deaths filmed by insurgents in Iraq.

"Before a terrorist event is going to occur there is usually a change in that organisation as it begins to prepare and plan and resource the event. In that context I can monitor a network in real time and monitor the change in behaviour before an event occurs," Dr McCulloh said.

"Social network analysis is to old-fashioned detective work what statistics is to intuition. It's applying mathematical rigour to what people have done before," he said.

So while social network analysis is an important tool for the military, the Federal government and Facebook Terms of ServiceFacebook Terms of Servicecounter-intelligence agencies, it does beg the question as to our privacy rights. While Facebook has changed their TOS (Terms of Service) to supposedly protect our private data, what is going to happen to our privacy rights in the future. As we are now witnessing with the interrogations of CIA members and potentially higher officials in the Bush Administration, (including Dick Cheney), rules are often bent if not broken in times of war.

Will Six Degrees of Separation and the mathematical equations of Game Theory produce a social network analysis that factors in the innocent activities of our daily lives and plots them into a formula that makes us look like suspects?  Here's hoping that subsequent Social Network Analysis remains a tool to surface a partial picture of corroborating evidence, but that our final conclusions are based on a comprehensive investigation that goes beyond just Social Network Analysis. I'm sure Kevin Bacon and John Forbes Nash Jr. would agree!

Aug 27, 2009
by Anonymous

6 degrees in your company

Mining opt-in social networks is certainly interesting on the FB front for marketing. Cell phone logs provide insight into potential terrorist networks.

Are we missing the most amazing and valuable social newtorks? The social network that exists within your company is alive and well and manifested in the electronic communication patterns of its employees. eTelemetry has a product - a black box - that analyzes this social network that's called MetronEBA - enterprise behavior analysis. It uncovers the real leaders in a company and informal collaborative groups. How work really gets done - see Rob Cross's books for more information also.