Most scholars agree that Paul of Tarsus is the actual author of the letter.
The letter itself names Paul (Saul) of Tarsus as its author, a claim that has never been seriously questioned, other than a few passages which differ in style from the rest of the work. According to the Bible, Paul was born into the tribe of Benjamin in Tarsus, the capital city of the Asia Minor province of Cilicia, later traveling to Jerusalem to become a rabbi of the sect of Judaism known as the Pharisees. He was most likely a member of the Sanhedrin. Though an Israelite, Paul was considered by the Roman Empire to be a free man and Roman citizen, as Tarsus was designated by the Romans as a "free city".
Having been trained as a rabbi, Paul was much more theological in his writings than many of the Biblical authors. He is considered by Christians to be one of the foremost Biblical authorities on Jesus, though, according to his own writings, he never even met Jesus. Paul supposedly converted to Christianity (not in the traditional sense, since at the time Christianity was considered a sect within Judaism) after being temporarily blinded by a flash of light that he claims was a vision he received of the resurrected Jesus while traveling the road to Damascus. His writings show that he was often in opposition to the ideas and teachings of the apostles who actually knew and learned from Jesus. At one point, he is said to have opposed the apostle Peter "to his face, because he was clearly in the wrong (Galatians 2:11)" on some dogmatic teachings.
1 Corinthians Chapter 11 contains a list of instructions regarding how men and women should present themselves in regards to head coverings and hair length.1 Corinthians 11:14-15 says
14 Doth not even nature itself teach you, that, if a man have long hair, it is a shame unto him?
15 But if a woman have long hair, it is a glory to her: for her hair is given her for a covering.
Some more conservative Christians interpret this as applying to all Christian men, while most Christians view it as being wrong in the culture of that particular place and time. None propose an answer to the question of how exactly nature teaches us that it is a shame for men to have long hair. For instance, male lions have long manes while lionesses do not.