[mysterypie]

The result is therefore quite boring. It's like saying famous actors have worked with other famous actors, and lots of actors can thereby trace their themselves through a chain of actors back to Charlie Chaplin. (Too bad it wasn't about genetics -- now that would have been interesting.)

[xapata]

The relationship between PhD student and advisor is often much more like apprentice and master than the relationship between two actors/actresses working together.

[jamestnz]

Indeed, perhaps a more apt analogy from acting would be the many famous actors who trained under Lee Strasberg (Al Pacino, Robert De Niro, Dustin Hoffman, Anne Bancroft, James Dean, Jane Fonda, Paul Newman, Ellen Burstyn and others).

Strasberg in turn was a student of the ideas of Konstantin Stanislavski[1].

And so it goes.

[1] https://en.wikipedia.org/wiki/Method_acting

[tgb]

In particular, one rarely has more than one advisor, perhaps two in some circumstances.

[beagle3]

A teacher/mentor is not the same as "worked with".

When Kevin Bacon appears in a film with X, who is the master, and who is the student?

[posterboy]

Obviously, Kevin Bacon is the root node of the graph, or rather the producer with the necessary vitamin C.

I also felt reminded of the Five Degrees of Kevin Bacon.

[dmichulke]

Having worked with is a 1:n relationship

Having an advisor is 1:1 (with a few exceptions like 2 PhDs or 2 advisors for one PhD)