Numerous states have set legal precedents regarding child custody disputes where the non-biological parent is determined to be a "psychological parent" and is therefore able to retain custody. In 1973, Goldstein, Freud, and Solnit, wrote their landmark book, Beyond the Best Interests of the Child. They opined:

Whether an adult becomes the psychological parent of a child is based thus on day-to-day interaction, companionship, and shared experiences. The role can be fulfilled either by a biological parent or by an adoptive parent or by any other caring adult—but never by an absent, inactive adult, whatever his biological or legal relationship to the child may be.