One of Shuvu’s books has a story about a family from Russia who
turned out to be descendants of the Chofetz Chaim. The mother was
aware that her (great-?)grandfather had been a respected rabbi.
If frumkeit or midos were a function of genetics (similar to whether one is left handed, or whether one is bald), what zechus would it be to do mitsvos?
A person might inherit certain traits, but he would have the
ability to go against them. “L’fum tza’aro agro” does mean
that whatever is easier earns less reward…