What role does humor play in helping the family or Augie cope with the situation?

Humor helps the Pullman family through some pretty difficult times. When their baby is hanging on for life, Augie's mother tells a humorous story of Augie's birth that is both funny and poignant Augie's father is pretty funny too using humor to smooth out the rough patches of life. He, for example, makes Augie crack up by making fun of Mr. Tushman's name.

"I started laughing, not even because I thought he was being that funny but because I wasn't in the mood to stay mad anymore."