Borromean rings are a configuration of three rings arranged so that no two rings are interlocked but all three together are.
Let me put that another way. If you look at any two of the three rings, and were able to take the third ring out of the equation, the first two rings would have nothing linking them; nothing in common. But once that third ring is introduced, all three of the rings are basically inextricable.
I find the concept fascinating, especially as I (immediately) tried to find a parallel example within human relationships, especially considering this key fact: the circles (people) comprising a Borromean Ring cannot be perfect — in order to actually work, they need to be imperfect — they have to be, in a word “eccentric” to greater or lesser degrees.
Historically, people have used such rings to symbolize strength in unity (A and B would fly apart, were it not for C), and that’s interesting… but equally interesting 1 is the interpretation that A and B could fly apart, if it weren’t for C.
I still can’t quite get my head around a ‘real’ example. To a degree, it’s easy: “Divorced Man A and Divorced Woman B would have no connection were it not for Shared Child C”; okay, yes, that works. Except that in order to be a true social Borromean Ring, the following would also have to be true: “Divorced Man A and Shared Child C would have no connection were it not for Divorced Woman B” and vice-versa.
I’m not saying such an example doesn’t exist — where, in a group of three people, any of the two would fly apart in the absence of the third — I just can’t seem to think of one.