In "My Sister, My Love," Joyce Carol Oates explores the dark side of American culture, particularly the obsession with popularity and fame. The narrative revolves around the impact of society's values on family dynamics and individual identity. Oates illustrates how the relentless pursuit of social recognition can lead to tragic consequences, particularly for children who are thrust into the spotlight.

The phrase, "Popular! In America, what else matters?" encapsulates the central theme of the book, reflecting a critique of a culture that prioritizes superficial success over genuine connections and moral values. Oates uses her characters to depict the emotional turmoil and pressures faced by those trying to navigate a world where popularity often equates to worth.