Tongyangxi also known as Shim-pua marriage in Taiwanese , was a tradition of arranged marriage

Arranged marriage

An arranged marriage is a practice in which someone other than the couple getting married makes the selection of the persons to be wed, meanwhile curtailing or avoiding the process of courtship. Such marriages had deep roots in royal and aristocratic families around the world...

 dating back to pre-modern China, in which a poor family would sell a child, a pre-adolescent

Adolescence

Adolescence is a transitional stage of physical and mental human development generally occurring between puberty and legal adulthood , but largely characterized as beginning and ending with the teenage stage...

 daughter to a richer family as a servant or a caretaker. In exchange, the girl would be married into the adopted family when both children reach puberty

Puberty

Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...

. The girl acts both as a daughter-in-law (to be married to the adopted family's young son in time to come) and free labour. The girl is usually a few years older than the male child. Due to the lower-class status of the girls, discrimination

Discrimination

Discrimination is the prejudicial treatment of an individual based on their membership in a certain group or category. It involves the actual behaviors towards groups such as excluding or restricting members of one group from opportunities that are available to another group. The term began to be...

 was often present, and slavery

Slavery

Slavery is a system under which people are treated as property to be bought and sold, and are forced to work. Slaves can be held against their will from the time of their capture, purchase or birth, and deprived of the right to leave, to refuse to work, or to demand compensation...

-like treatment was not uncommon.

A direct translation of "shim-pua" is simply "little daughter-in-law", while "tongyangxi" means "child daughter-in-law."

These marriages were often unsuccessful. This has been explained as a demonstration of the Westermarck effect

Westermarck effect

The Westermarck effect, or reverse sexual imprinting, is a hypothetical psychological effect through which people who live in close domestic proximity during the first few years of their lives become desensitized to later sexual attraction. This phenomenon was first hypothesized by Finnish...

.

In China, the practice was outlawed by the Communist Party of China

Communist Party of China

The Communist Party of China , also known as the Chinese Communist Party , is the founding and ruling political party of the People's Republic of China...

 after they seized power in 1949.

In Taiwan, shim-pua marriage fell out of practice in the 1970s due to increased wealth from Taiwan's economic success, making such arrangements unnecessary.

Related concepts

"Zhao-Zhui" (招贅) is a related custom by which a wealthy family that lacks an heir might take in a boy child. The boy would take on the familial name of his new family, and typically would marry the family's daughter.