4.74 Degrees of Separation on Facebook

First time accepted submitter perryizgr8 writes "Facebook Data Team has taken all the friends data of everyone on Facebook and analyzed it, finding out the shortest distance between every two persons. They can now confidently say that the average degree of separation between any two humans is 4.74, not six as previously claimed by various entities."

Comments

Bad Claim

[Ibiwan]

1) As others have pointed out, not all humans are on Facebook. I'm sure the FB researchers would be hard-pressed to believe that, though.

More importantly,
2) The "six degrees" is supposed to be the MAXIMUM linkage between any two people -- not the average. Good job disproving something nobody ever claimed, guys!

Misrepresentation of the original research

[smellsofbikes]

If anyone wants to read a good analysis of the *original* six-degrees-of-separation study, Malcolm Gladwell wrote about it in The New Yorker about ten years ago. (You may wish to skip ahead to part 3.) The researchers -- and this was Stanley Milgram, of the infamous Milgram Experiment involving people's willingness to torture other people -- gave people envelopes addressed to a specific person, and told them to write their names on the envelopes then give them to someone they thought might know the addressee. When all the envelopes came through, they analyzed both the number of hops and the route. (The average was somewhere between 5 and 6 hops, with some being higher. There is no assurance this is the shortest route, but their initial estimates were 100 hops, not five.) The most interesting part was that of the envelopes that reached their destination, more than half came through just three people. It's the discussion of those people, the ones who know people in various different close-knit communities, that matters: they're the connection points.

Re:Disagree

[similar_name]

I think it would be interesting to see the average degrees of separation for each individual. One person might have an average of 9 degrees separation to everyone else while another individual might average 3. Cross that number with standard demographics data and look at any correlations. x being people not on Facebook you could still compare people with 3 + x degrees vs 9 + x degrees.

Re:Skewed Data?

[meza]

Maybe I'm different from other Facebook users then, sure I have some people on my friends list that I only met once at a party and now don't even remember who they are. But in real life there are so many more people that I know casually and would say I'm "connected to" that I am not friends with on Facebook, such as: my hair dresser, my dentist, my boss, other colleagues, all the people I ever went to school with (of whom I've probably befriended less than 25% on Facebook) all the teachers I ever had, my neighbours, distant relatives, my siblings friends etc etc.

So I think if we included everyone we know in real life the degree of separation would probably go down, not up.

Re:Skewed Data?

[DavidTC]

Except that the idea of degrees of separation isn't 'friends', it's 'People who know each other'. No one ever said those people had to be 'friends'. No one's ever bothered to try to define exactly what that means, although at minimum you probably have to have exchanged words with them at some point, and have a way of contacting them.

Granted, on Facebook, it's probably slightly too loose even with that requirement. Apparently, some people on Facebook go around friending anyone who shows up as a likely friend, regardless of whether or not they actually know the person. And sometimes the other person accepts that request. Clicking on someone's picture and sending a request is probably not actually 'knowing' someone.

So assuming, on average, one of those bogus 'knowing people' per chain of '4.74' people, which caused the calculation to skip a number that really should be there (They aren't X's friend but they are the friend of the friend of X) ...it comes out to essentially what people have been saying all along.

Which is weird, because as far as I know, 'six degrees' isn't based on any scientific information...it's from playing a game with Kevin Bacon. (Which is not about who 'knows' each other, it's about who's been in movies and TV shows with each other.)

Re:Not exactly.

[Anonymous Coward]

Of course, that incredibly vague metric doesn't really explain what a degree of separation is.

Is it just people you personally know? Or does it count:
- people you've only met, even if you've forgotten them?
- people you work with?
- people you work in the same building as (regardless of whether you work for the same company)?
- people you work in the same company as (regardless of whether you've ever met them)?
- people you've done business with at some point (including the check-out clerk at a shop or their manager, whom you've never met)?
- people you've passed on the street?
- people you've ridden a bus with?
- neighbors, whether you've ever talked to them or not? (And in how large of a radius?)

So 6 degrees of ... whatever. You could say everyone shares only 1 degree since they've breathed the same atmosphere or you could massively increase the steps by making a "degree of separation" limited to parent-child genealogical links. It's all just lies, damn lies, and statistics anyway.

Re:Disagree

[Kjella]

I think it would be interesting to see the average degrees of separation for each individual. One person might have an average of 9 degrees separation to everyone else while another individual might average 3.

Extremely unlikely. Remember that the number of people connected grow exponentially. Your friends are few. Friends of friends are many. Friends of friends of friends is insanely many. Even if you're a tightly knit bunch already after 1-2 steps you're bound to have many connected to the "main" network. Personally I know I have people in my friend list that have gone through every class list since primary school - that's how I'm their friend. If you have *one* of those people as friends, or even friend of friend you're extremely well "connected" even if you can count your Facebook friends on one hand.

Likewise it's not likely to go as low as 3 because if you say 100 friends average then the most people you can reach in 4 connections is 100^4 = 100 million. The only reason I think you'd go as high as 9 would be if you're an isolated tribe deep in the Amazons with 3 degrees of separation to the few researchers that are there, that are 6 degrees from the rest of the world.

You can do the math the other way around, to connect 7 billion people with six degrees of separation each degree of separation must expand the network 7 000 000 000^(1 / 6) = 44 times. Is that likely? Yes. That doesn't mean 44 friends though, it's more complicated than that. The first degree is my direct friends, that is simple. The second degree is friends of friends minus those I'm friends with directly but only counting each person once. So if five of my friends went to the same school and know the same person (that I don't), he's only counted once. So the formula is

Unique persons brought into the network * 1 +
Shared people brought into the netowork * 1/n where n are the people shared with +
People already known to the network * 0 = 44.

That doesn't seem that unreasonable, to my friends my work mates and family are new, to my work mates my friends and family are new and to my family my friends and work mates are new. Different school history, work history, different family, lived different places... each degree brings plenty new. Take for example my study mates, very many of them studied abroad. Each of them is like a new boom of contacts entirely new to the network.