England is known for its class structure. Downton Abbey, anyone? The Iqbals and the Joneses are working-class families. Some of these characters seem content with that, and others seem to want more. When Irie, Millat, and Magid come into contact with a middle-class family (yep, the Chalfens), we see more clearly some of the differences that define families of different social statuses or classes. But we also see that families are just families. The Chalfens, the Iqbals, and the Joneses all struggle with intergenerational and cultural conflicts. And, at the conclusion of the novel, they all end up in the same place. Literally.
The action in White Teeth starts moving in a noticeably different direction after Irie and Millat start spending time at the Chalfens' house—and the Chalfens' middle-class lifestyle has more than a little to do with this dramatic turn.
In White Teeth, class does more to define the characters' roles in society than race does.