Transformation
Transformation is perhaps the most prominent theme in American Born Chinese, as the desire to change form and therefore identity is the trait that unites the Monkey King and Jin and shows how their stories work as parallels. Early in the book, the Monkey King trains himself in Kung-Fu and Taoist disciplines in order to transcend his lowly status as a monkey and become a supreme being whose power rivals the creator of the universe. In Jin's storyline, Jin learns as a child that he can grow up to be a transformer—i.e. the shape-shifting toy he likes to play with—if he sacrifices his soul. Later, he makes good on this advice when he escapes his shameful identity as an American-born Chinese boy and adopts the Danny alter-ego. The two storylines collide when Chin-Kee reveals his true form as the Monkey King and teaches Jin that he could have saved himself five hundred years under a pile of rocks if only he accepted that it is good to live as a monkey. With this lesson, Jin accepts his own true form.
Folklore
Folklore plays an important role in American Born Chinese, as the entire story of the Monkey King is a retelling of the Chinese folktale of Sun Wukong. Though the Sun Wukong character can be traced as far back as the Song Dynasty (960–1279 AD), Sun Wukong was prominently featured in the 16th-century Chinese epic novel Journey to the West. Yang blends this folklore source material with his semi-autobiographical depiction of Jin, using the Monkey King's desire for transformation and eventual self-acceptance as a parallel to Jin's journey through adolescent self-loathing toward a mature acceptance of his true identity.
Discontent and Acceptance
Discontent that arises from being frustrated with one's circumstances is another of the novel's major themes. For the Monkey King, dissatisfaction festers when he isn't recognized by the heavens as a supreme being. As a punishment and lesson for the vengeance he seeks, the creator of the universe traps the Monkey King under a pile of rubble for five hundred years. Eventually, by releasing his discontent and accepting himself, the Monkey King frees himself from the rocks. As a parallel, Jin's discontent comes from feeling excluded from the mainstream white majority at his school. This leads Jin to fantasize about transforming into Danny, a popular white boy. Adopting this idealized identity, Jin loses touch with his true identity. At the end of the book, the Monkey King imparts his wisdom: that he learned it is good to be a monkey. Through acceptance, Jin overcomes his discontent and meets with Wei-Chen as a symbolic means of reconnecting with Chinese culture and true friendship. Just like the Monkey King, Jin overcomes discontent and finds peace through acceptance.
Racial Discrimination
The theme of racial discrimination surfaces consistently throughout the novel. Discrimination is usually practiced in the form of casually racist comments directed toward Jin, Wei-Chen, or Suzy, though discrimination is sometimes handled in more overtly. Chin-Kee, for instance, embodies every anti-Chinese caricature America has conjured since the late 1800s, and therefore encapsulates discrimination in an absurd package. Discrimination also functions in the novel in more nuanced ways: using euphemistic and indirect language, Greg intervenes to keep Jin from dating Amelia, as Greg believes they aren't suited for each other. Later, he tells Amelia that Jin is a bit of a "geek"; presumably, this is his coded way of socially excluding Jin because he is Chinese.
Identity
Identity—particularly the desire to escape one's identity—is another of the novel's major themes. Several characters struggle with their identities. The Monkey King isn't satisfied with his identity as a monkey, and so does everything he can to transform into a being who is bigger and stronger and more invulnerable to attack. Similarly, Jin struggles with identity as an ethnically Chinese American; he wishes to escape this identity by refusing his Chinese heritage and trying to act like a mainstream white American—a struggle that is metaphorically represented in his alter-ego Danny. Wei-Chen also struggles with identity. Though he is the Monkey King's son and has been tasked with the challenge of living a mortal life for forty years while avoiding human vice, Wei-Chen loses faith in humanity and devotes himself to a life of pleasure-seeking.
Assimilation
Even more insidious than the casual racism Jin experiences is the incidental pressure to integrate into and absorb mainstream American culture. Feeling that he is an outsider, Jin wishes to be able to participate in the popular mainstream culture of his school. In a symbolic effort, he curls his naturally straight hair to better resemble Greg. Later, Jin's desire to blend into his social surroundings leads him to dissociate from his Chinese identity through the alter-ego Danny, an embodiment of the conventional white American teenager.
Social Pressure
The theme of social pressure is depicted in the novel through the sometimes–overt, sometimes-unconscious pressure characters feel from their social spheres. The Monkey King feels a social pressure to wear shoes and not to be a monkey, while Jin feels the social pressure to conceal his Chinese cultural background while at school—unless he is comfortable being made an object of humiliation. Jin later wields social pressure against Wei-Chen: in reaction to the way bullies make Jin feel like an outsider whose culture isn't acceptable, Jin tells Wei-Chen to act less like he is "fresh off the boat."