David Baxter PhD
Late Founder
Famous Six Degrees of Separation Study was a Fraud
by Rebecca Skloot
January 15, 2009
Every time I see that someone has joined the Six Degrees of Separation experiment group on Facebook (which now has more than 2.5 million people in it), I think about something I posted about on Culture Dish a few years ago (and have updated here): At this point, pretty much everyone knows the theory of Six Degrees of Separation: That everyone in the world somehow connected through a chain of six people. What most people don't know is, the results from the study that supposedly proved the theory were actually bogus ...
The phrase "Six Degrees of Separation" was coined by Stanley Milgram -- the famous and largely controversial social psychologist who originally conducted the Milgram Shock Experiment, examining people's obedience to authority by testing how many would administer potentially lethal electric shocks to screaming victims (a study that was oddly just repeated).
For his Six Degrees of Separation study, Milgram asked people to give a letter to other people they knew by name, then he tracked how long it took for each letter to end up in the hands of a person the original sender didn't know in another city. He reported that the average number of people it took to get from the sender to an unknown person was six. Hence, the phrase "six degrees of separation." But apparently no one ever bothered to look into his data, until now:
by Rebecca Skloot
January 15, 2009
Every time I see that someone has joined the Six Degrees of Separation experiment group on Facebook (which now has more than 2.5 million people in it), I think about something I posted about on Culture Dish a few years ago (and have updated here): At this point, pretty much everyone knows the theory of Six Degrees of Separation: That everyone in the world somehow connected through a chain of six people. What most people don't know is, the results from the study that supposedly proved the theory were actually bogus ...
The phrase "Six Degrees of Separation" was coined by Stanley Milgram -- the famous and largely controversial social psychologist who originally conducted the Milgram Shock Experiment, examining people's obedience to authority by testing how many would administer potentially lethal electric shocks to screaming victims (a study that was oddly just repeated).
For his Six Degrees of Separation study, Milgram asked people to give a letter to other people they knew by name, then he tracked how long it took for each letter to end up in the hands of a person the original sender didn't know in another city. He reported that the average number of people it took to get from the sender to an unknown person was six. Hence, the phrase "six degrees of separation." But apparently no one ever bothered to look into his data, until now:
Judith Kleinfeld, a professor psychology at Alaska Fairbanks University, went back to Milgram's original research notes and found something surprising. It turned out, she told us, that 95% of the letters sent out had failed to reach the target. Not only did they fail to get there in six steps, they failed to get there at all. Milgram was a giant figure in his world of research, but here was evidence that the claim he was famously associated with was not supported by his experiments.
Which means the whole Six Degrees of Separation thing is more fiction than solid statistics (much to the dismay of the many the films, plays and books written using Six Degrees as their driving force). What's interesting is that several researchers did follow up studies and claimed to find similar results, but those studies all had the same problem as Miilgram's:In the most recent, two years ago, only 3% of letters reached their target. "If 95 or 97 letters out of 100 never reached their target, would you say it was proof of six degrees of separation? So why do we want to believe this?" ..."The pleasing idea that we live in a 'small world' where people are connected by 'six degrees of separation' may be the academic equivalent of an urban myth," she says.
Kleinfeld has her journal article detailing the backstory of Milgram's study and her findings about his research here. It's seriously fascinating stuff, so check it out (she's also posted a shorter follow up here).
