Let’s see if we know the whole world in six steps
It’s something you’ve probably heard about on a birthday party somewhere. That we are actually connected with every single person in the world just via six people that know each other. So everyone is actually your friend’s friend’s friend’s friend’s friend’s friend.
The idea was first explored by sociologist Stanley Milgram. Yes, that’s the one from the Milgram-experiment, with those electric shocks. In 1967 he did something very different. He started a send-forward mail to 96 randomly selected people in the United States and looked at how many inboxes the mail had to pass before reaching a target person in Boston. The average was six.
This rather small experiment has been replicated on a bigger scale various times and a number between six and seven keeps popping up. In 2008 for instance researchers analyzed the data of Microsoft Messenger instant-messaging system. It was a dataset of 30 billion conversations among 240 million people. The average path length between these users was 6.6.
The problem remains, however, that the results only say something about the kind of people that were included in the studies. Those are people that use email or instant messaging service or any other network that has been analyzed.
If people living in a jungle tribe in Brazil or on a mountain peek in Nepal were counted in, this could change the number a little bit. But the results still remain quite inapprehensible. And I’ve already seen some cell phones in surprisingly isolated areas.
Photo: Flickr, My Tudut
Source: Scientific American,
2.Dodds, P. S., Muhamad, R. & Watts, D. J. (2008). Planetary-scale views on an instant-messaging network Science DOI: 10.1145/1367497.1367620