It’s rare for a sociological study to wind up a part of pop culture, but that’s what has happened to Stanley Milgram’s “small world” study, which posits that all of the people on the planet are connected to one another through an average of six acquaintances—or through six degrees of separation. The first popular use of Milgram’s study was the John Guare play Six Degrees of Separation, which was later made into a movie. Then came the Six Degrees of Kevin Bacon game, created by college students, in which players must connect the actor to another actor by no more than six other people. In 2006 there was the TV show Six Degrees, which told the story of six characters who, according to the network, “go about their lives without realizing the impact they are having on one another.” Even the popular PBS series American Masters has jumped on the six degrees bandwagon, with a Web game that allows you to pick any two of the accomplished people it has profiled through the years—everyone from Aaron Copland to William Styron—and find the links that connect them. How are Truman Capote and Lucille Ball connected? This is the Web engine’s answer: Truman Capote is connected to Lena Horne because Horne appeared in the book Observations by Capote and Richard Avedon. Horne is connected to Lucille Ball because they—along with Judy Garland and Gene Kelly—were in the Ziegfeld Follies.
Professor Judith Kleinfeld
Image © Calvin White
But perhaps the most interesting use of Milgram’s study came from Judith Kleinfeld, a psychology professor at the University of Alaska at Fairbanks. In 2002 she realized she had a problem in her classroom. “My graduate students insisted that social science research was nothing more than the systematic study of what you already know,” she says. To challenge them, she decided to have them replicate social scientist Milgram’s small world study. The more Kleinfeld thought about the assignment, the better she liked it. They could update the technique, she thought. Milgram had used regular mail as the mode of communication between acquaintances, but her students could use e-mail. Maybe they would find that the Internet had closed the gap further. They could even, Kleinfeld fantasized, track down some of the participants in the original study and see if they were game for another round. To do it right, though, she needed to look through Milgram’s papers, which his wife had donated to Yale University after his death in 1984. Kleinfeld boarded a plane and made her way to Yale’s Sterling Memorial Library in New Haven, Connecticut, where she donned white gloves and rummaged through boxes 48 and 49 of the Milgram collection.
Milgram’s original study design was simple: He gave 60 people in Wichita, Kansas, envelopes and the name of a target person—a stranger—along with a few details of that person’s life. Their mission: to get that envelope to someone they knew on a first-name basis who then might be able to pass the envelope a step closer to the target person. In a subsequent study, he used two starter populations in Nebraska and one in Boston to reach a target in Sharon, Massachusetts.
The idea was to see how many steps it would take to get each envelope to the target person. In his 1967 write-up of his work in the premiere issue of Psychology Today, Milgram shared one particularly riveting anecdote from the first study—that of an envelope that made its way from a wheat farmer in Kansas to the target, a divinity student’s wife in Cambridge, Massachusetts, with just two connections. However, he also reported that the average number of connections (not the maximum number, as people sometimes mistakenly believe) between strangers was six—still astonishingly few.
Milgram’s study made headlines and resonated in the public’s imagination. Were each of us really only six people removed from a long-lost childhood friend, a lower-caste field worker in India, or any celebrity? Could we really find our way to, say, Stephen Hawking or Brad Pitt or even Osama bin Laden in just six steps? Of course, this raises the question: If we’re only six people away from bin Laden, why hasn’t he been tracked down and captured? The answer, as Kleinfeld discovered, is complicated. It involves the misleading reporting of statistical data, the seductive power of a pleasing idea, and the vagaries of human behavior.
When Kleinfeld began sifting through Milgram’s original data at Yale, she was surprised to find how much that data seemed to conflict with what Milgram had reported. Only 3 of the 60 envelopes in the original study had reached the divinity student’s wife—a completion rate of just 5 percent. The second study reported a completion rate of only 29 percent. Moreover, Milgram recruited subjects for two of his studies by buying mailing lists, which tend to be biased in favor of high-income people with high numbers of connections. Other sociological work has shown that low-income people are generally able to reach other individuals with low incomes, but not those with high incomes.
