The fact that one parent has been the child's primary caretaker is often considered but is not enough to guarantee a custody award. A 1993 Stanford study of petitions to modify custody found that these awards were highly inconsistent, and attributed them in many cases to personal gender biases held by judges. Homosexual parents in the 1990s still posed dilemmas for judges. See also gay and lesbian rights. Adoption Adoptions can provide courts with another source of custody disputes.
Most state laws require that both birth parents give consent before their child can be adopted.
Such a law was at issue in a custody battle over Jessica DeBoer, born in Iowa in 1991 and adopted by a Michigan couple. DeBoer's birth mother later married DeBoer's birth father and they sought and won custody of DeBoer in Iowa, based on the father's never having consented to the adoption. The adoptive parents then won in the Michigan courts, based on an analysis of the child's best interests. On appeal, the Michigan Supreme Court reversed, declaring that under federal law, Iowa had jurisdiction in this case, and that unless a child's birth parents are unfit, an unrelated person may not retain custody. Family ties are often a compelling factor for judges even when birth relatives other than parents are involved.