The most all-encompassing theme of the story is the struggle to define self-identity. In a world intent on labeling women in every way (daughter, wife, mother, submissive, inferior, etc.), Bet must push herself to step outside those designations and discover the fabric of her own selfhood.

When readers first meet Bet, she is fully invested in being a mother. Her clothes are disheveled, she is physically and emotionally depleted, and she has no personality separate from her son. Every decision is focused on either meeting Arnold’s needs or presenting him favorably to the world. Unlike her ex-husband, she has not yet abandoned her responsibilities. On the train, she watches Arnold closely, even when he’s sleeping, and she is hypervigilant about potential threats to him. Readers have no indication that Bet could ever be anything else but a mother until she closes her eyes and remembers her childhood, literally and figuratively denying her role.

When Arnold’s head “[snaps] up” (34), Bet returns to her motherly duties, desperately trying to keep him entertained. Later, when the conductor has a confrontation with another passenger over money, Bet “[looks] gratefully” at her because the incident made Arnold laugh. This entire scene exemplifies Bet’s feeling of entrapment in her current identity.