There are few Westerners who can understand the Chinese practice of concubinage as it was practiced up until the 1930s. In actuality, the practice of concubinage is a logical outgrowth of the Chinese family structure, particularly as it applied to the position of women in the Chinese family, in which the male was the supreme authority.
As a daughter, a Chinese girl had no rights at all. In fact, the birth of a female child was considered to be both a time of sadness and a time of an evil omen, as we see when Wang Lung considers the birth of his daughters to be signs that the gods are not favoring him. No celebration is held if a girl is born: Wang Lung even threatens the gods at the birth of his first grandchild. A female child was considered to be a liability to the family because she was thought to be only a temporary member of the family — someone who had to be supported until she could be married. And since she was married at an early age, she could never perform enough work in order to pay for the expenses for her years in the family. Wang Lung gives his daughter away when she is thirteen because he can no longer guarantee her virginity. After she leaves him, Wang Lung never sees her again. Also, in poor families, a daughter could be sold as a slave to a rich man; O-lan, for example, was sold when she was a young girl, and Wang Lung is even tempted to sell his "fool." Note, too, that Wang Lung, when he becomes rich, buys "slaves" (girls from poor families) for all the members of his household.
Thus, a daughter is trained to become a subservient person to her husband's will, and, as a wife, she is constantly expected to obey her husband without question. For example, when Wang Lung discovers that O-lan has a sack of jewels, he asks for them and she obeys without question--except for the bold request to keep two small pearls which she later surrenders to him when he demands them.
