You are familiar with the debate in the psychological community over which has the greatest influence on our behavior, Nature or Nurture (genetics or environment).
It seems that William Shakespeare knew of it, too.
In his play, The Tempest, first performed on November 1, 1611, he penned the line:
"A devil, a born devil, on whose nature nurture can never stick."
Evidently, The Bard came down on the side of nature being stronger than nurture.