When I was there, it was real easy to tell who was from what Group:
1st - Baht chains and cheap cologne
5th - Looked like someone had kicked their dog and always asking for a job.
7th - a Big Street Gang. Harley shirts and no respect for anything other than other 7th Groupers.
10th - Smoked pipes and wore smoking jackets. Always ate Ramen to save money for their next TDY.
SWC - Looked like someone had kicked their dog and would beg to go anywhere but 10th Group.
Probably all changed now. A lot of people want to go to whatever Group has the war.
I think people tend to take on some of the characteristics of their AOs.
7th Group guys picked up the Latin "manana" thing a little.
10th Group guys are a lot like the French.