I'm involved with two clubs for a sport I'm passionate about.
On the face of it, they're very similar. Same number if training sessions a week, run on very similar lines. Same geographical area and same demographic of membership. Similar achievement levels and compete in the same events. Both organiise occasional low key social events and the odd trip away. There's a friendly rivalry between the two clubs, but a lot of members belong to both, with one being their second claim.
On a personal level they are entirely different. One is full of laid back people who rub along without drama, very supportive of any small achievements, don't take much interest in each other's personal life.
The other is always having big fallings out, lots of affairs between members, even more gossip, catiness when the "wrong" people do well, lots ofOTT congratulations when the popular ones do well.
How does that happen? What is it that makes similar clubs, with some cross over of members, so different?