[paul.fr]

I can't see it being fact myself, although i have never tried it...i know.

Has anyone tried to prove it, one way or the other? Is it plain bonkers?

[another_someone]

There has been two experiments on this matter, the one that possibly introduced the idea (the 'Small World Experiment', by Stanley Migram), and a later internet experiment.

The interpretation often given to the results (that the maximum separation between two people is 6 hops) is totally wrong.  What the experiments did conclude (although not prove, as much could be said about the small sample size, and the basis of selection of the subjects) is that the average separation between any two people is 6 hops (since for some of the random routes, there was only a single hop between source and destination, so there must have been a number of cases where much more than 6 hops were required, and some end to end connections simply were not made, and there seems to have been little follow up as to why those connections did not happen, and how that should be interpreted in terms of the answer - it might even simply be argued that if there are substantially more than 6 hops from source to destination, it is likely that the connection will not be made at all).

[DoctorBeaver]

I think there's a lot in favour of it. You'd be surprised how simple it is to find a route between people who do not directly know each other. For instance, I used to date a lady who was chairperson of her local Conservative Association (she was actually a very attractive, 40-year-old blonde - not 1 of the prune-faced, blue-rinse brigade!). She had met, among others, Ted Heath and Maggie Thatcher. They, obviously, had met many heads of state. So, with only 2 steps, my connection goes almost worldwide.

Similarly, my connections from university can put me in contact with people worldwide.

In fact, I would say it is far more likely these days than when Milgram conducted his experiment. The internet has broken down international and class boundaries. All of us on this site are no more than a couple of hops from Stephen Hawking and that would not have been possible even 10 years ago.

[another_someone]

Is not the point you are making that it is very easy to find a connection to a well connected person.

I think the difficulty is with trying to find connections to socially isolated persons (could a tramp in London connect with a tramp in Paris as easily as a university professor in Oxfordshire connect with a politician in New York?).

My membership of Mensa also brings me in contact with a great many people who move in both political and academic as well as business circles.  But are there not still many people who don't belong to any such groups?

In a sense, part of the problem with these experiments is that in order to take part in these experiments you have to already have some connection with academia, and so people who simply are socially isolated from any of the major network hubs within society would simply never be visible in these experiments.

[DoctorBeaver]

No, that's not my point.

I know travellers, homeless people, junkies etc. My connection to heads of state means that those people also have a connection; it's just 1 extra step. At the other end of the chain there may well be the same thing, so a homeless person in this country could have a connection to a homeless person in the USA in just 7 steps.

homeless UK -> me -> Sue -> Maggie -> US president -> US equivalent of Sue -> US equivalent of me -> homeless USA

OK, it's 7 degrees of separation not 6, but it makes the point.

[Bored chemist]

A tramp in a big city might still be well connected (in a rather odd sense) but a man in the middle of a poor country might not be. He might know the local "head man" but even they might not know many paople outside the village so the chains get longer.
Even then it's not suprising that you don't need many links.

There's another glitch in the chain though. Say some homeless guy asks you to contact his long lost homeless brother in the states.
You remember Sue and she remembers Maggie. Maggie and the US president probabaly remember eachother . Does the president remember the US equivalent of Sue?
Does she remember your counterpart (OK probably) Do they, in turn remember the tramp?
That's where the chain would fall apart.
If the original guy happened to ask me rather than you the same thing goes wrong. I met David Cameron and, if he hasn't met Mr Bush them he knows Tony Blair who has.
It's just possible that if I wrote to Mr cameron he would forward my letter to Mr Blair. At least he could- he could find an address/ contact point. Mr Blair could certainly forward it to Mr Bush. (Even I know roughly where he lives) That's where it starts to get tricky. Say he knows the target lives in LA. He could give it to some state representative and get it to CA- probably to LA itself, but where to go from there? There are probably dozens or hundreds of "homeless shelters" in a city like that. How would you find the guy? (a newspaper ad is cheating).

[DoctorBeaver]

Is it actually about being able to contact someone, or just to show the connection? I always thought it was the latter.

[Bored chemist]

According to the wiki article cited above, the original experiment was to contact the target person.
"Though the experiment went through several variations, Milgram typically chose individuals in the U.S. cities Omaha, Wichita, and Boston, to be the start and end points of a chain of correspondence. These cities were selected because they represented a great distance in the United States, both socially and geographically.[1]
Information packets were initially sent to randomly selected individuals in Omaha or Wichita. They included letters, which detailed the study's purpose, and basic information about a target contact person in Boston. It additionally contained a roster on which they could write their own name, as well as business reply cards that were pre-addressed to Harvard.
Upon receiving the invitation to participate, the recipient was asked whether he or she personally knew the contact person described in the letter. If so, the person was to forward the letter directly to that person. For the purposes of this study, knowing someone "personally" is defined as knowing them on a first-name basis.
In the more likely case that the person did not personally know the target, then the person was to think of a friend or relative they know personally that is more likely to know the target. They were then directed to sign their name on the roster and forward the packet to that person. A postcard was also mailed to the researchers at Harvard so that they could track the chain's progression toward the target.
When and if the package eventually reached the contact person in Boston, the researchers could examine the roster to count the number of times it had been forwarded from person to person. Additionally, for packages that never reached the destination, the incoming postcards helped identify the break point in the chain. "

[DoctorBeaver]

Fair enough. We only touched on this briefly at uni (we were actually looking at another of Milgram's experiments) and it was simply the connection that was examined, not being able to actually get a message from A to B.

[paul.fr]

Does anyone fancy trying this? Our own little naked scientist experiment, it could be fun and interesting.

[another_someone]

Does anyone fancy trying this? Our own little naked scientist experiment, it could be fun and interesting.

I don't think I could.  The problem is that the experiment involves not just me (or some other person who volunteers themselves) but also their friends and acquaintances (who are by definition an integral part of the experiment), so I would have to volunteer other people for whom I would feel I have no right to make such a commitment.

OK, this is me, and I am by no means suggesting that this is the way other people would feel; but the key point is that the fact that you are relying on volunteers, who for various reasons might not volunteer, would mean you do not have a randomised sample.

In any case, how would you choose the other end of the network?  Simple saying "How many contacts would it take for you to connect to Tom Cruise?" is one thing; but that is a very different from asking how many links in the chain between you and a farmer in an Indian village (as for trying to get a message through to Osama bin Laden through named intermediaries - that would be an interesting exercise, but I shall refrain from undertaking it).

[DoctorBeaver]

(as for trying to get a message through to Osama bin Laden through named intermediaries - that would be an interesting exercise, but I shall refrain from undertaking it).

I wonder if that's been tried?

FOLLOW THAT POSTMAN, MEN!

[JimBob]

As for Ben Laden you can get a message to his son, George (above person, not the son but I sometimes wonder [] ), who is married to an English woman and is into western culture, renouncing his father

[another_someone]

As for Ben Laden you can get a message to his son, George (above person, not the son but I sometimes wonder [] ), who is married to an English woman and is into western culture, renouncing his father

I thought they divorced, but I may be wrong.

Yes, he does claim to have renounced his father (the fact that I use the word claim is not to say that I have reason to disbelieve him, only that the matter is unprovable one way or the other).