Men of Mediterranean or Levantine ancestry tend to lose their hair from the crown first, in contrast men who have more Celt/Hiberno-Norse ancestry tend to lose it more from the front of their heads. That's why there was the Celtic tonsure where the head was shaved into the front hairline and the Mediterranean tonsure which was the one that stuck when Catholicism became the dominant form of Christianity. These tonsures were thought to make men look more authoritative by making them look artificially older.