The Philosophy of Being Loyal

Lately, due to recent observations. I have been wondering a lot about loyalty. Exactly what is it and why do people go through desperate lengths to prove their loyalty to something or someone. I understand that recently in class that we have been talking about patriotism, but that is a bit different from what I am talking about. If you have ever read Alexandra Robbin's book Pledged: The Secret Life of Sororities, you would understand my concern. If you have even walked around campus and heard the stories of hazing from sororities, you would understand where I am coming from.  Girls and guys degrading themselves to be apart of a sisterhood/brotherhood. Doing things and wearing things that they wouldn't normally do or wear over a certain period of time just to prove their loyalty so they can be accepted by a particular group of people and be labeled "cool and touch." I am sorry but I am not going to ever degrade myself, and sleep with a guy as an initiation into a "club." Neither would I let my "Big sisters" or "Big brothers" dress me up and leave me in the middle of nowhere only to let me find my way back by myself at night. (These are all instances in the book by the way which is a real account of real sororities). Do you know the number of girls (and guys) that have died or been hurt executing these orders put out by their "older pledge masters." I mean of course they are to blame, but the people who put themselves through it are to blame also. Why do the things you are told to do, just to show how "loyal" you are. Then at the end of this period, you wouldn't knwo that these people went through the things they went to because htey are all buddy buddy with the person who at one point in time was calling them ugly fat good for nothings. So with that said What exactly is loyalty and why do people go through such lengths?