Does hair grow back?

I've had that exact haircut for much of the game. My beard has been shaved many times, but my hair has never seemed to grow back.

The hair will reportedly grow back for the default "clean shave", but not for any of the DLC haircuts or beards.

As others have mentioned the facial hair will grow back only if you only choose either the clean shaven or trim beard options. If you ever choose one of the other DLC facial hair options then your facial hair stops growing.

As far as the hair on your head that doesn't grow with one exception. If you end up being thrown in jail in Toussaint your hair cut will change to the 'long and loose' hair cut. That is the only time I've seen your hair cut change or grow after styling it (assuming of course your hair wasn't styled that way prior to going to jail).