‘Six Degrees’ Just Won’t Die

By Jennifer Barone | March 19, 2008 9:43 am

Another study–this one analyzing the largest social network ever–has found that people are connected by about 6 degrees of separation. Here, the sample consisted of 240 million people on Mircrosoft’s instant messaging service. And lo, when scientists finished with them, the “average path length” among the IMers was 6.6.

Nature News’ story on the study (login required for full access) finds this to be “spookily close” to Stanley Milgram’s original small-world study in the 1960s that started the whole six-degrees mania. But as DISCOVER wrote in February, Milgram’s experiment wasn’t replicated, suffered from an abysmally low response rate, and looked at people on mailing lists who were probably of similar socioeconomic status and thus more likely to share connections.

The IM study has some similar limitations. Since it’s looking at instant messaging as the method of connection, the sample includes only people with access to computers. It does span different continents, but North America, Japan, and Europe are overrepresented, while only scattered data was available from Africa and nothing at all from North Korea. Age was an issue as well, with 15- to 30-year-olds dominating the participant group.

The study authors say that they expect their basic findings would hold true if everyone on Earth could be included. They do acknowledge that the magic number might increase a bit, but somehow “seven degrees of separation” just doesn’t have the same ring to it.

You can read the instant-messaging study abstract or download the full paper here.

For more on network analysis, check out “From Muhammad Ali to Grandma Rose.”


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


Quirky, funny, and surprising science news from the edge of the known universe.

See More

Collapse bottom bar