How is poverty a cycle for Junior's family?

Junior explains that his father and his mother, Agnes Adams, both raised on the reservation and each had aspirations. Sadly, they also fell into the same cycle of poverty as many of their peers, which Junior claims is responsible for them having become alcoholics. Junior’s mother is intelligent, and she once wanted to go to college. His father is a talented singer, who once dreamed of becoming a jazz musician. Unfortunately, neither received any support or help to leave the reservation, and as a result, they abandoned their childhood dreams. Mary, Junior’s older sister, was a promising student and aspiring writer. She retreated into her parents’ basement after high school graduation..... she simply gave up. After seeing Junior pursuing his dreams by going to Reardan, however, she marries a professional gambler and moves to a reservation in Montana. She professes to be happy with her new life, which is sadly cut short after a fire consumes the trailer in which she and her husband are living.