Carl Zimmer has a fascinating article up at Yale Environment 360 on network theory in the environmental sciences. As he puts it:
By mapping the connections between species, they are discovering some of the rules by which all ecological networks are organized, and how these rules help foster biodiversity. They’re also studying how biological invasions, overfishing, and other threats are reorganizing these networks, and possibly putting them at risk of collapse.
Carl starts out by invoking a well-known heuristic for the small-world network phenomenon, the “Six Degrees of Kevin Bacon” game. It’s overplayed, but it really does illustrate how such networks, well, work. For those one or two people in the world who are unfamiliar with the game, the idea is to measure the number of degrees of separation between any actor and Kevin Bacon. As an example, let’s take this guy, who’s a long-time member of the writers’ group I joined last year. Clif was in Silent Running with Ron Rifkin, who was in JFK with Kevin Bacon, so Clif has a “Bacon Number” of two.
“Six degrees of Kevin Bacon” is, of course, a play on the “Six Degrees of Separation” concept, the notion that the average number of personal acquaintanceships linking any two people on the planet will be about six. In the words of Mark Buchanan in his book Nexus: Small Worlds and the Groundbreaking Theory of Networks
One of these experiments was performed by psychologist, Stanley Milgram, in order to create a picture of the web of interconnections within a group of people. To do this he sent letters to a random selection of people living in Nebraska and Kansas asking them to forward the letter to a stockbroker friend of his living in Boston but did not give them the address. To forward the letter he asked them to send it only to someone they know personally who they thought was socially closer to the stockbroker. Milgram found that most of the letters made it to his friend in Boston and most of the letters made it in just six mailings.
As it happens, The Raven and I were briefly talking about a variation of the Bacon game a couple days ago, which gives me a way of riffing on Carl’s post in my usual way of Making This All About Me. The version is called the “handshake number” concept, which Stephen Jay Gould wrote about a couple times: how many handshakes does it take to get from you to, say, Stalin?
I can get from myself to Stalin in three handshakes for sure. When I worked at the one nursery still open within the District of Columbia back in the mid-1980s, I waited on — and exchanged handshakes with — Clark Clifford, who among many other things was Harry S Truman’s White House Counsel. Truman, of course, shook Stalin’s hand on July 17 1945 at Potsdam. Clifford links me to a whole lot of people, in fact. Through him I’m two handshakes away from every US President who served in the second half of the Twentieth Century, and through them with one more handshake to probably tens of thousands of notables from Elizabeth II to Martin Luther King to Marilyn Monroe.
(Actually, though the Bacon number and handshake number concepts don’t match precisely, as you can co-star in a film with someone you’ve never met, I can probably get to Ms. Monroe in one less step via my writers’ group friends.)
My jobs with environmental groups over the years have provided some interesting handshake paths. Dave Brower, for instance, connects me to hundreds of veterans of the environmental movement famous and unsung, likely the most prominent being Wallace Stegner and Ansel Adams. Brower -> Adams puts me at least as close to Dorothea Lange and Everett Ruess as I am to Stalin and Mao. Brower->Stegner gets me to about four-fifths of the American writers I admire, given Stegner’s long career of mentoring younger writers from Ed Abbey to Raymond Carver, and working with contemporaries like DeVoto. I actually have a few other lines to Stegner, given his long involvement in Bay Area life.
Others whose hands I’ve shaken in the course of my work life include Jerry Brown (through whom I get linked to all kinds of people from the Dalai Lama to Linda Ronstadt), the departed Hopi Elder Thomas Banyacya, Ed Begley, Jr., writer Gary Nabhan (who links me to probably 80 percent of the Seri ironwood carving community), etc. etc. etc. I’ve had a pretty damned rewarding career so far and met some great folks, so I may have more prominent handshakes nailed to my wall than a lot of people.
But the point isn’t that I’m well-connected. The point is that we all are. Some of my most direct connections to the world’s most famous and/or notorious people came while I was working a retail job at minimum wage. Others came as a result of knowing people who aren’t themselves famous, whether the teacher who studied with a renowned scholar or the one-time romantic interest whose grandparents knew a lot of famous writers or whatever. Some came through just being in the right place at the right time, as when I walked to the train station one afternoon and there, shaking people’s hands as they entered the station, were Gray Davis and Cruz Bustamante who would a week later become California’s Governor and Lieutenant Governor, respectively. When I was very young Paul Erdős gave a talk at my school. We shook hands after I answered a question correctly that he had posed to the assembled kids. As I recall, the answer to his question was “aleph-one,” which by coincidence is also my Erdős number. The one I like most came as a result merely of having the right brother: back in Buffalo in the 1970s, Craig was a high school classmate of the late David Hampton, the con artist whose deceptions inspired the play “Six Degrees of Separation”. Which makes me two degrees of separation from “Six Degrees of Separation.”
Really, the surprising thing once you start tracing things out is not which people you can establish links to but how many of those links are redundant. I can, for instance, get to Ronald Reagan in four or fewer handshakes in at least three ways and probably more, given his membership in not only the realms of state and national politics but also through Hollywood. (Clif gets me there via Henry Fonda.) That’s the thing about living networks: they tend to offer multiple ways to get from point A to point B. Which somehow doesn’t make it any easier to score good drugs these days.