Facebook, Yahoo Test Six Degrees Theory

Duncan Watts on modernizing a 1960s-era experiment

A classic sociology experiment is getting the Facebook treatment. This week, Yahoo Research launched an online study to test the oft-repeated—but as yet unresolved—theory that anyone in the world can reach anyone else in “six degrees of separation.” Using Facebook and its social graph of 750 million users, Yahoo’s “Small World Experiment” invites people worldwide to attempt to send a message to a specified “target” by creating an online chain of connections.