Do children who live under an abusive father become abusive fathers themselves?
Yes. The context states that by far the greatest percentage of children who lived under an abusive father become abusive fathers themselves when they become fathers. It describes this generational carryover as a kind of human pecking order, where abuse passes down through family relationships.
Les teaches that abuse is one of the qualities that carries from generation to generation. He points to present-day statements from psychologists and psychiatrists and says that a child who has lived under an abusive father will, by far the greatest percentage of the time, become an abusive father himself. Les compares this to the pecking order in livestock and poultry. In the human makeup, he explains, an abusive father and husband abuses his wife, and she in turn often turns on the children; those children then need someone to go on.