Hair loss in men might have to do with testosterone.  A study of men in ancient times sheds a little light on this theory.  They discovered that eunuchs kept all their hair.  These were men that were castrated on purpose for slavery or their genitals were wounded in battle and nonfunctioning.  Either way these men were not creating testosterone but they never went bald.  By studying these men the discovery was made that hair loss has something to do with testosterone.  Some old wives tales are that if you get hair loss it is a gene that is passed down from the mothers father.  This is not true. 

The gene can come from either the mother or the father.  Also you cannot cause hair loss by wearing a hat.  I used to hear my dad say that all the time.  He would tell my brothers to take their hats off or they would wish that they had when they are sixty years old.  My brothers would look at him like he was a crazy man.  A crazy man with a bald head!  However a theory that you can hang your hat on is that a diet full of fatty foods might be linked with hair loss.  Don’t hang your hats up just yet, this theory is not proven.