Tradition/Custom
Hair
I went to Chabad for dinner with my friends Lindsey and Alex one night and we ended up sitting next to Rabbi David, who told us a lot about Orthodox Jewish culture. He told us that the reason they keep their beards so long and never shave is because they feel it is wrong to take a knife to something that God created. They see growing out their beard as part of devoting themselves to God, and showing their dedication to Him. They also believe that God wants them to keep their hair long in order to single them out for people to recognize them as followers of Him.
Hair can be used as a representation of who you are, your femininity, your masculinity if you get a short crew cut (although men these days are much more free to do what they want with their hair than anyone else), or your religion. Many people and groups take hair very seriously, making rules about hair upkeep part of their culture. It can be an easy way to show off a certain part of you. But, hair should only do that if you want it to. It should never drag you down, or be forced upon you to keep you in a certain group. Women should not be forced to have long hair to maintain their femininity. Women can have short hair and be feminine all the same.