Mood throughout I Know Why the Caged Bird Sings is determined largely by the point-of-view character, Maya Angelou herself. Angelou relates these tales to the reader in retrospect, looking back on a childhood filled with adversity. The mood during these sections verges on grim, particularly during the chapters recounting Angelou's sexual assault at the hands of Mr. Freeman. As Angelou ages and learns how to manage her trauma (both from the assault and from the racist oppression of American society), the mood shifts to one of perseverance and hope.
I Know Why the Caged Bird Sings is a coming-of-age novel (Bildungsroman) and thus follows those genre conventions, in part, when it comes to establishing mood. Coming-of-age novels typically feature a child or adolescent protagonist, tracking their growth and development as they learn about more complex, worldly issues. Such narratives tend to follow certain patterns with regards to mood. The story may begin on relatively neutral ground before delving into heavier topics, accompanied by a rather grim or unsettled mood. Young narrators react with great shock and upset when they discover another of society's ills (racism, misogyny, injustice, etc.). As they learn how to deal with these ills and cope with their trauma—as Angelou does—the mood shifts to one of hope, ending the narrative on a positive or sometimes bittersweet note. Coming-of-age stories tend not to maintain a grim or bleak mood throughout, given that these narratives usually center children and are thematically focused on growth and change.