I was raised in a reformed Pentecostal church. The main reason usually given is because of a passage in Revelations that deals with men being indistinguishable from women in the "end times." (Too lazy to look it up right now, sorry). Therefore, women must have long hair, men must have short hair, women can't wear pants (typically) and men -certainly- can't wear anything feminine. The other physical requirements generally have to do with modesty.
Somewhere in Corinthians, Paul mentions that women's hair are their head covering. So short hair will lessen the covering, I think. Someone approached me about this and I still think, if it is your hair you can chop away. Anyway, that's probably the Pentecostal logic.
Hello, my name is Pastor Tony den Hartog. There is really no rationale for hairstyle or any other legislation for Christian behavior. All these things are really old Law concepts to control behavior by law and legislation. They do not apply
to Christian Church. You can see they same control in Islam where woman have to wear their habit on their head to cover their face and hair. This is all law. Jesus redeemed us from the curse of the controlling Law so if you like you can search my website: http://freedomvoice.net where you will find freedom from all legislation and behavior patterns. Blessings. Pastor Tony.
Beware of "Pastor" Tony his arguments are umbilical. refer to the scriptures above. Jesus was the sacrifice for our sins, but we still have to follow him. Corinthians is very plain about women cutting their hair. Yes it is your hair and you can do whatever you wish with it, but by the same token, you can do anything you want at all, but that doesn't mean that you will go to Heaven. I think it is wise to follow the Bible instead of saying that your body is yours and you can do with it as you wish. The Bible also tells us that our bodies are temples of the Holy Ghost. This is of course if we are Christians. How can the temple of the Holy Ghost be Holy if it is not taken care of according to the Word of God? Hope this helps