when the man vistshis old home but his son is almost afarid to stay there long why does his son fear this and how does it relate to an eariler passage

This depends on waht earlier passage you are referring to. I think there is a certain amount of alienation here. The man reflects on his own childhood of warmth and family. This is a childhood the boy never knew. The boy feels the calm in his father and reflects that he has never known this.