What role does race play in this novel?

Race does not play a major role in The Bell Jar, but it does figure in as a subject for Esther's judgment, to some extent. In a novel about a character's conflicts of perception (pointedly including self-perception) and values, Esther's observations of race can be noted as one of many examples of her embattled sense of her place in the world. Race, as so many other labels, can be seen as part of Esther's tendency to look at the world categorically. 

Outside of her early comments on Peruvians, perhaps the most notable episode in the text relating to race comes relatively late in the novel. In it we see Esther using language that distances her racially from an attendant in the hospital. 

While at the private hospital (where Doctor Nolan treats her), Esther has an encounter with an African American staff member who she refers to as "the Negro."

During a dinner scene, Esther remarks on the fact that the meal includes two kinds of beans: 

"Now I knew perfectly well you didn't serve two kinds of beans together at a meal. Beans and carrots, or beans and peas, maybe, but never beans and beans. The Negro was just trying to see how much we would take." 

When Esther reprimands the man at one point, he responds by making "an insolent bow" and calling Esther "Miss Mucky-Muck." The episode ends with Esther kicking the man in the leg.

In the scene that follows, Esther appears to be experiencing a psychotic episode as she delights in knocking over a tray in front of a nurse. The "Negro" fits into this episode as well when his face is spotted at the window grating when Esther is wheeled into a locked room.

We should note a few things here. First, Esther has lost the sense of restraint that had encumbered her in the first half of the novel. In lashing out at the African American figure, she is choosing a person she feels is an easy target, yet she would not have done this at the outset of the novel.

The changes in Esther seen here are ugly, but they are also part of her growth. These are the throes of recovery and they show Esther taking on a power that she initially abuses.

Also, having spent much of the novel judging others, passively and actively, Esther is now being judged. She is at the mercy of the nurses and "the Negro" too. Abusing both the white nurse and the Black staff member, we can see that race is not the principal issue here—status is the principal issue.

One of Esther's most notable habits is her tendency to categorize people. She divides the social world into a variety of categories and applies a certain status to each. For Esther, this tendency is linked to her identity crisis as she cannot see a way to attain a positive identity. For instance, due to her categorical way of looking at the world, Esther feels that there is no way to straddle the boundaries between an identity as a mother and as a writer.

In her identity crisis, Esther is caught up in a drive to attain stability and, to some extent, status. Afraid of the judgments of the world and unable to find a way to achieve an integral identity, Esther breaks down and attempts suicide. The course of her treatment sees her learning to assert herself in her environment, to some extent, while still relying on her sense of a divided social world.