The Question and Answer section for That Was Then, This is Now is a great resource to ask questions, find answers, and discuss the novel.
What chapter is this in?
Byron begins to change his attitude when he see the dynamic, caring and loving relationships in Cathy's family. As a result, Byron begins to see the world around him in a new light.... he learns about empathy and compassion.
I think Mark is more accepting of change than Bryan is. Mark is used to not having stability and participates in high risk activities, like selling drugs, that lead to unpredictable outcomes.