I suggest you do a search of threads with "fratty" in the title. There are quite a few that talk about this same subject.
You might also look at:
Dress Code Across the U.S.
Northern Preppy vs. Southern Preppy
Any fratty colleges outside of south?
What makes Greek life "hot" in the south?
South vs. North?
As you read through these threads, you might note that this topic often has high trainwreck potential.
(And as I don't have much else to do tonight obviously, and I guess I'm feeling old and crotchety, I'll just say that here is one Southerner who will be so glad when the word "fratty" is out of style and people are preppy again.)