Complexity and Social Networks Blog

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21 August 2006

The emergence of the structuralist view of social networks

I recently completed Lin Freeman’s book on the history of social network analysis—I strongly recommend it. This is a first hand account by one of the remarkable figures and driving forces of the field, and the result is both insightful and personal.

The book is temporally organized, beginning with the prehistory of social network analysis. It does a superb job of weaving together threads of the antecedents of social network analysis pre-1930s (going well beyond Simmel, to Comte, Huber, Hobson, Almack, Galton, Botts, and others). It then turns to the “modern” age of social network analysis, beginning with Moreno’s work on sociometry, and then to the work of Homans and others in the 1930s. It then moves through the “dark ages” of the 1940s to 60s, to the “renaissance” of social network analysis, in part driven by Harrison White and students in the 1970s.

There are a number of things that make this a must read for those invested in the field. First, I think it offers an expansive intellectual history of the area that is simply not available anywhere else. Second, it offers a view of the personalities and the relationships within the field—e.g., that Moreno was a difficult personality, and that this may have played a role in the progress (or lack thereof) in sociometry. Further, the tracing of the personal and professional pedigrees of the key actors in the field was really quite powerful (accentuated by pictures of many of the key characters).

I do have a few minor quibbles. For example, the characterization of the 1940s to 1960s as the “dark ages,” I think, is unfair. Now, he means a very particular thing by this description, which is the lack of a self-aware school of thought based on the “structuralist perspective” on networks, which may be reasonably accurate. However, much of the most creative work in social network analysis (which he discusses)—from Newcomb to Festinger to Bavelas) was done in this period. In fact, it may have been the very lack of a self-aware paradigm that helped the field move forward during this time. A smaller quibble, btw, is that he does not do justice to Newcomb’s contributions to the field. I would say, with his studies on Bennington, and later Michigan, students are some of the landmarks in the field. In this same vein, I would have been very interested in a discussion of why social network analysis moved from largely social psychological moorings in the 1950s (think Festinger, Newcomb, and others) to largely sociological by the 1970s. Even the social network perspective on social influence, such a natural fit, largely drifted out of psychology, kept alive within sociology by Friedkin and Johnsen and others, and, to a certain extent, by Huckfeldt and Sprague and collaborators in political science. It is an intriguing question, with particular resonance today, as the disciplines interested in social network analysis are shifting significantly in the present (as discussed in earlier blog entries).

An additional puzzle, in thinking about the sequel to this book decades in the future, is that social network analysis, I believe, is shifting away from the structuralist paradigm of constraining, slow changing social networks, to a more dynamic or even episodic view of interactions.

In any case, this is a wonderful book—interesting and enjoyable to anyone who is deeply interested in the emergence and evolution of social network analysis over the last 100 years.

Linton Freeman. 2004. The Development of Social Network Analysis: A Study in the Sociology of Science, Vancouver, BC: Empirical Press.

http://www.amazon.com/gp/product/1594577145/sr=8-7/qid=1155870157/ref=sr_1_7/102-0280882-7590571?ie=UTF8">Link

Posted by David Lazer at 9:30 AM | Comments (0)

17 August 2006

NSA wiretapping ruled unconstitutional

Returning to the NSA thread for a moment, a judge in Detroit today ruled that the NSA wiretapping program is unconstitutional. Quoting from the Washington Post:

"U.S. District Judge Anna Diggs Taylor wrote in a strongly-worded 43-page opinion that the NSA wiretapping program violates privacy and free-speech rights and the constitutional separation of powers between the three branches of government. She also found that it violates a 1978 law set up to oversee clandestine surveillance."

Here is a copy of the decision:
http://www.washingtonpost.com/wp-srv/nation/documents/wiretap_ruling.pdf

Posted by David Lazer at 9:26 PM | Comments (0)

16 August 2006

"Network elasticity" and "individual plasticity"

I briefly want to plug these two book end constructs that I framed in a paper I wrote some years ago in the Journal of Mathematical Sociology ("The Co-evolution of Network and Individual"), which examined how networks and nodes co-evolve. Essentially, network elasticity captures how endogenous the network is—how much nodes get to choose who they connect to. Individual plasticity, in turn, captures how endogenous “attributes" are—how much individuals are affected by who they are connected to. In this paper (and the discussion here) I apply these ideas to social influence processes, but the concepts are more general than that. I would argue that different social systems differ dramatically in how elastic their networks are, and how plastic the nodes are, which, in turn, has certain systemic implications.

The idea that individuals affect their network as compared to being affected by their network are sometimes placed at opposite ends of the spectrum; but of course, they are really orthogonal processes. Since this paper was written, statistical tools (e.g., by Tom Snijders and his team with Siena) have been refined to examine just such a coevolutionary process. My focus is really on something different than estimating the underlying transition probabilities for the change in state of particular relationships or nodes.

Rather, what I am focused on are the long run dynamic systemic consequences of different levels of elasticity and plasticity. For example, in Co-evolution, I examined the social network within a government agency, where the social structure was very rigid, where the ties of a new person were pretty much the same as their predecessor, and that individuals entered when their were early in their professional career and thus pretty malleable. The result was that structure drove attitudes, not the other way around. One could produce a 2 x 2 typology of networks and plausible resulting dynamics:

High plasticity and low elasticity: homophilous network, where the social structure will drive attitudes (e.g., traditional bureaucracy).

High elasticity and low plasticity: homophilous network, where social systems will polarize along nodal characteristics.

High elasticity and high plasticity: dual possibilities of emerging with a homogeneous, cohesive, network, or polarized cliques that do not talk to each other.

Low elasticity and low plasticity: heterophilous network.

Of course, the above depends a lot on the determinants of the social structure; an inelastic network that forces you to talk with likeminded people has very different implications than an inelastic network that forces you to talk with people who are different from you.

“The Co-evolution of Individual and Network" Journal of Mathematical Sociology, January 2001, 69-108.

Posted by David Lazer at 10:20 AM | Comments (0)

13 August 2006

Quantifying Social Networks in Africa - EPROM

Wanted to spread the word that we are now launching EPROM (Entrepreneurial Programming and Research On Mobiles) jointly at MIT and the University of Nairobi. The premise behind the project comes from the fact that today’s mobile phones are designed to meet Western needs. Subscribers in developing countries, however, now represent the majority of mobile phone users worldwide (1.4 billion mobile phone subscribers live in the developing world!). We have put particular emphasis on Africa because it is currently the fastest growing mobile phone market in the world, and I’ve moved to Kenya for the year to get the project off the ground.

What Kenyans are starting to do with their phones is amazing. Today, in my small town of Kilifi, I can buy milk, pay for a taxi ride, even check the local vegetable prices on my mobile... I describe this phenomenon in more detail here.

To further our understanding of the underlying factors driving entrepreneurship using mobile phones, we are involving several students as research assistants to pursue research on behavioral and mobile phone usage patterns. We will be distributing Nokia ‘smartphones’ to fifty individuals in different demographics and log their behavior over the course of six months. The phones will have a custom application that continuously logs location, nearby peers, communication and phone usage statistics, similar to the data collected for 100 people during the Reality Mining project at MIT. In this previous research, we generated models of our subjects’ lives with such precision that they could be used to accurately predict subsequent behavior. Based solely on data logged by our custom phone application, we have successfully shown that after two months logging it is possible not only to predict behavior, but also to infer friendships, differentiate demographics, validate survey responses, and even quantify the dynamics of an organization. It is our hope that this data will provide an analogous quantitative description of Kenyan social networks and mobile phone usage behaviors.

Cheers from Kenya...

Posted by Nathan Eagle at 7:53 AM | Comments (0)

8 August 2006

Information Sharing and Institutional Impact

A very interesting piece in today’s Washington Post about information sharing in homeland security—excerpts below. I am also linking to the DHS IG report on the Homeland Security Information Network. The report and article do highlight (1) the social component to information sharing (but also the institutional impact on those social networks); and (2) the limitation of technology at this time in overcoming the key bottlenecks in necessary information sharing.

For full article click here

For report click here

In Arizona, Officials Share Data the Old-Fashioned Way
Wednesday, August 9, 2006; Page A07

On a recent drug bust in Phoenix, law enforcement officials found a vial of white powder that made them suspicious. They called Arizona's joint federal, state and local counterterrorism center, which dispatched a team to investigateThe powder turned out to be triacetone triperoxide (TATP), a highly sensitive explosive similar to the substance that failed "shoe bomber" Richard Reid was found to be carrying on a transatlantic flight in December 2001. Word of the discovery reached the FBI in Washington within 10 minutes. Although arrests and interrogations later determined there was no terrorist connection, it was just the kind of rapid information-sharing envisioned by intelligence changes implemented after the Sept. 11, 2001, attacks caught the intelligence community by surprise.

But the news did not travel through any of the sophisticated new high-speed communications systems built to facilitate rapid information flow between Washington and domestic counterterrorism's front lines. Instead, it went the old-fashioned way, with an Arizona police official walking across the hall to tell his friend in the local FBI counterterrorist task force, who then picked up the telephone and called headquarters.

According to a June report by the DHS inspector general, 2 percent of 9,500 registered users of the Homeland Security Information Network -- the department's two-way computer portal -- logged on to the system each day.
Although 360 state officials were cleared to use HSIN's separate secret portal, users averaged 27 a month.

For Beasley, who has retired from the state police and has been asked by Washington to help teach other state centers how to operate efficiently, success in Arizona began with his relationship with Churay. "When you talk about Washington and all those systems they're developing that are going to interconnect everybody in the country and everybody in the world, that's good," he said.

"But the reality is, on a day-to-day basis you have to go into those systems," he [Beasley, who designed the state center in AZ] added. "Most people, if they're operational, don't have the time. That's where that personal relationship, day to day, is absolutely critical. This business is built on trust."

Posted by David Lazer at 11:40 PM | Comments (0)