I think that the film stresses how the divergent cultural expression in South America is something that Ernesto interprets in a materialist and Marxist manner. For all the cultural expressions in the boys' travels, Fuser sees the collision between the haves and have- nots cutting through different cultures. The exploitation that the latter endures at the hands of the former is the common denominator that Fuser sees as dominant in all cultures. From the affluent beginning of their journey, to the interactions with the Communist couple and the copper mines, as well as the culmination of the journey in the leper colony, different cultural expressions can be reduced to a hierarchical structure in which the voices of those who are on the bottom struggle to be heard.
Fuser becomes aware of this and commits himself to listening these voices, acting upon making right that which is wrong. His actions in the leper colony that seek to bring together the haves and the have nots is a reflection of how he perceives the universality of class struggle in different cultural expressions of the good. In this, one element of the different cultures featured in the film is the presence of social inequality within them.