As Wang Lung grows in wealth, this family that has been historically and traditionally tied to the land, grows away from the land and evolves into a new social class.
Wang Lung himself, in the year of drought, becomes bored and restless without his land to work on. He begins visiting the tea shop in town. His restlessness leads to lust, which draws him away from his wife O-lan, and toward a mistress, Lotus. Because his wealth is still so new to him, he does not know how to act in the tea shop, and he feels grossly out of place. But he believes that he deserves something because he is rich.
It seemed to Wang Lung then that he must prove at any cost to this woman that he was more than a mere country fellow... (Chapter 18).
Wang Lung's wealth also causes him to resent O-lan because she is ugly, and as a result of this, and her husband's mistress, she withdraws further and dies very sad and lonely. Where once she was her husband's partner in the fields and in bearing him children, she becomes worthless when he has enough wealth to pay laborers to work the land.
Wang Lung's oldest son, who is sent away to school instead of learning to farm, grows away from the deep sense of respect that Wang Lung had for his own father, and becomes selfish and spoiled. He makes demands of his father for finer things. He disrespects his father's rules and gives in to his own young lusts and desires. Even when he marries, his wife, unlike his own mother, is a "city girl" who screams out in childbirth. This son demands that a woman be found to nurse the child because he will not have his own wife losing her beauty.
And finally, as a result of Wang Lung's wealth, his despicable uncle, with wife and son, move into Wang Lung's house. They are lazy, selfish, and full of evil. It is discovered that Wang Lung's uncle is part of a prominent group of bandits, and his presence in Wang Lung's family (and house) is what has protected Wang Lung from looters in times of drought and flood. So Wang Lung must appease this extended family. Their presence in the house causes resentment and stirs unrest. Wang Lung's young nephew threatens the innocence of Wang Lung's daughters, who he sends away at young ages to the houses of their betrothed for protection.
As the family gains wealth and moves away from its ties to the earth, it grows apart, grows restless, and invites seeds of selfishness, idleness, and greed to grow.