Well, Larkin, is no guide, the coastal shelf is the shallow part of the sea around dry land. Coastal shelves do not deepen.
There is no element of genetic inheritance in abuse. It can be handed down by nurture, but not nature. Sounds to me like some theory someone has made up and touted around tinseltown, where it has gone down a bomb, a way of blaming others for everything so you do not have do anything to help yourself. If it is genetic, Harry will not be able to help himself repeat his parent's mistakes. Or is he getting his excuses in in advance, for when his children grow up and talk about their dysfunctional childhood!