The Boy Scouts are very close to fraternities as well...
Actually, if you do some digging, you'll notice a link between the Boy Scouts of America, Alpha Phi Omega, and Sigma Alpha Epsilon. There was another thread a while ago about this, but it goes something like this... APO was founded specifically on the tenents of the Boy Scout Oath and Law. Most/All of APO's 14 founders were former scouts, and 8 of the 14 founders, all of whom were former scouts, were SAEs (Penn Gamma Chapter).
Anyway, as an Eagle Scout, the predominant reason why I chose SAE was because I was one of a half-dozen
Eagle Scouts among the group and the chapter was/still is one of the smaller ones on campus. Becoming an Eagle Scout isn't easy... something like only 2% or so of all scouts actually make it (% could be a little higher now, but probably not by much), so for 6 of them to be found in one small group was enough evidence for me of the quality and character of the men in my chapter. I found out about the BSA/APO/SAE link after the fact, but it only served to confirm my decision as the right one!