The attitude displayed regarding family is perhaps the most pronounced cultural marker presented in the novel. Expectations placed on the children, roles designated for members of the family unit, and various other obligations all serve to underscore the importance of the family as the central concept of the culture - not the individual.
In so-called Anglo society, we can see a far greater emphasis placed on the individual as the basic unit of culture and society, even as the family is defined as the basic unit of reproduction and social instruction as it commonly is carried out. The family is important in this society, but not as central and as privileged in its value as in the Latino society depicted in the novel.
Explicit expectations and defined family roles are assigned to each character in the novel, from Tony to his brothers to Ultima and even Tony's uncles. In Tony's case, we can clearly see how the cultural position of the family, in its pre-eminent importance, leads to some of Tony's internal conflicts as he struggles to find himself.
Tony feels all of his family’s conflicting expectations weighing down upon him, and he wishes to find his own identity.
For reasons that seem to be related, Tony's brothers feel that they must leave home to establish themselves and define their own identities. This is a breach of the established cultural code of values, but it serves to demonstrate those values in the breach, as it were, as Gabriel and Maria respond to their sons' departure.