Ugly Little Monkeys depicts Mexican-American families navigating assimilation and Catholic devotion amid prejudice, while the youth mariachi group's surrogate brotherhood reveals institutional abuse by a priestly authority figure, with filmmakers David E. Valdez and Enrique Castillo leveraging personal ties and survivor testimonies for intimate access. The central question probes how cultural heritage and chosen bonds sustain communities despite undermined parental and clerical guidance, tilting toward progressive framings of family resilience over traditional norms.

The documentary reveals sexual abuse perpetrated by the Catholic priests who founded and led the youth mariachi group, depicting the church's clergy as abusive and hypocritical while highlighting the long-term trauma inflicted on the young members. This portrayal underscores institutional failures within Catholicism without offering counterbalancing positive elements for the faith itself. The narrative condemns the predatory actions tied to the religious authority.