The tender years doctrine is a legal principle in family law since the late nineteenth century. In common law, it presumes that during a child's "tender" years (generally regarded as the age of four and under), the mother should have custody of the child. The doctrine often arises in divorce proceedings.
Historically, English family law gave custody of the children to the father after a divorce. Until the 19th century, the women had few individual rights and obligations, most being derived through their fathers or husbands. In the early nineteenth century, Caroline Norton, a prominent social reformer author, journalist, and society beauty, began to campaign for the right of women to have custody of their children. Norton, who had undergone a divorce and been deprived of her children, worked with politicians and eventually was able to convince the British Parliament to enact legislation to protect mothers' rights, with the Custody of Infants Act 1839, which gave some discretion to the judge in a child custody case and established a presumption of maternal custody for children under the age of seven years maintaining the responsibility from financial support to their husbands. In 1873 the Parliament extended the presumption of maternal custody until a child reached sixteen. The doctrine spread in many states of the world because of the British Empire. By the end of the 20th century, the doctrine was abolished in most of the United States and Europe.
Tender years doctrine was also frequently used in the 20th century being gradually replaced towards the end of the century, in the legislation of most states, by the "best interests of the child" doctrine of custody. Furthermore, several courts have held that the tender years doctrine violates the equal protection clause of the Fourteenth Amendment to the U.S. Constitution.