The views of Wallerstein and Kelly have shaped California's recent laws on joint custody and mandatory mediation. These measures appear to represent a departure from the views of Goldstein and others favoring designation of one parent as the custodial parent. However, Wallerstein and Kelly recognize the need for flexibility in determining the most appropriate arrangement. The concept of the psychological parent is compatible with both theoretical positions. Goldstein and others believe that only one parent should be the custodial parent, however. Mediators must realize that they are working with people under extreme stress and should try to keep changes for the child at a minimum. Thus, they must consider the nature of each parent-child relationship. The child may have one, two, several, or no custodial parents. The mediator must protect important relationships, consider the sincerity of the parents' motives, respect the childrens' perceptions, proceed with gradual shifts, and monitor the changes carefully. The overriding considerations should be to place the needs of the child first and to consider the relationship between the child and the parents as sacred. 11 references.