Tender years doctrine
The tender years doctrine is a legal principle which has existed in family law since the late nineteenth century. This common law doctrine 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 the English Family Law gave custody of the children to the father, in case of divorce. Until the nineteenth century the women had few individual rights, most of their rights being derived through their fathers or husbands. In the early nineteenth century, Mrs. Caroline Norton, a prominent British feminist, 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 the politicians of those times and eventually was able to convince the British Parliament to enact legislation to protect mothers' rights. The result was 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. In 1873 the Parliament extended the presumption of maternal custody until a child reached sixteen years of age. This doctrine spread then in majority of the states of the world as England was controlling a wide empire. By the end of the 20th century this doctrine was abolished in the majority of the states of USA and Europe.
In United States
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.
The Tender Years doctrine was gradually abolished in the majority of the states of the EU. In those states the joint custody is the rule after divorce or the separation of the parents. The Principles of the European Family Law regarding the parental responsibilities mention in clear that the two parents are equal and their parental responsibilities should neither be affected by the dissolution or annulment of the marriage or other formal relationship nor by the legal or factual separation between the parents.
Maternal preference versus tender years doctrine
Critics of the family court system, and in particular father's rights groups, contend that although the tender years doctrine has formally been replaced by the best interests of the child rule, the older doctrine is still, in practice, the means by which child custody is primarily determined in family courts nationwide. Despite this, in 1989 the Massachusetts Supreme Court’s Gender Bias Study reported that "Fathers who actively seek custody obtain either primary or joint physical custody over 70% of the time." 
Critics maintain that the father must prove the mother to be an unfit parent before he is awarded primary custody, while the mother need not prove the father unfit in order to win custody herself, and that this is contrary to the equal protection clause.
- Blakesley, Christopher L. 1981. "Child Custody and Parental Authority in France, Louisiana and Other States of the United States: A Comparative Analysis" Boston College International and Comparative Law Review, Volume 4, Issue 2.
- Bookspan, Phyllis T. 1993. "From a Tender Years Presumption to a Primary Parent Presumption: Has Anything Really Changed? … Should It?", Brigham Young University Journal of Public Law 8 (January).
- Katz, Sanford N. 1992. "'That They May Thrive' Goal of Child Custody: Reflections on the Apparent Erosion of the Tender Years Presumption and the Emergence of the Primary Caretaker Presumption." Journal of Contemporary Health Law and Policy, Catholic University 8 (spring).
- McLain, Lynn. 1997. "Children Are Losing Maryland's 'Tender Years' War." University of Baltimore Law Review 27 (fall).
- Pica, Derek A. 1999. "The Tender Years Doctrine: Is It Still the Law?" Advocate (Idaho) 38 (January).
- Radke, Lynn E. 1993. "Michigan's New Hearsay Exception: The 'Reinstatement' of the Common Law Tender Years Rule." University of Detroit Mercy Law Review 70 (winter).
- Rinella, Lori. 1995. "Children of Tender Years and Contributory Negligence." UMKC Law Review 63 (spring).
- Tender Years Doctrine on TheFreeDictionary.Com
- Criteria for Custody Awards
- Wroath, John (1998). Until They Are Seven, The Origins of Women's Legal Rights. Waterside Press. ISBN 1 872 870 57 0.
- Cynthia A. McNeely (1998). "LAGGING BEHIND THE TIMES: PARENTHOOD, CUSTODY, AND GENDER BIAS IN THE FAMILY COURT".
- C. Gail Vasterling (1989). "Child Custody Modification Under the Uniform Marriage and Divorce Act: A Statute to End the Tug-of-War?". Washington University Law Review 67. p. 925.
Many courts consider the maternal preference doctrine to be gender discriminatory. The Supreme Court of Alabama, for example, held that "the tender years presumption represents an unconstitutional gender-based classification which discriminates between fathers and mothers in child custody proceedings solely on the basis of sex."
- The document is issued by Commission on European Family Law and can be consulted here. See Principle 3:10.