I could be 140 pounds, and have a 95 pound bench press, yet if I had a shaved head, I would look strong as hell. I don’t know how the psychology works, but having a bare noggin makes you appear much stronger than you actually are. Lots of athletes take advantage of this to gain an edge over the competition. This tennis pro suddenly became a legend when he shaved his head; I forgot his name.
Maybe having long hair makes you look more like a girl? Does the bald edge disappear in cultures where men can have long hair like women?
There should be some study comparing athletes of different hair status. There just should be.