A psychologist specializing in child-custody issues argues forcefully for overhauling the adversarial process by which custody decisions are usually made--and for abandoning the ``motherhood mystique,'' the assumption that mothers have superior custody rights because they are uniquely suited for raising children. Warshak bases his arguments on numerous research studies, including his own Texas Custody Research Project, a 15-year study of 64 white, mostly middle-class families, one third of whom were intact, one third with children in the custody of the father, and one third with children in the custody of the mother. He cites data indicating that fathers are just as important to the psychological development of their children as are mothers, and that children in father-custody homes do as well as those in mother-custody homes. Indeed, he presents evidence that boys generally do better in the custody of fathers. But Warshak is not arguing to substitute father custody for mother custody. His research indicates that children of divorce do best when they are involved meaningfully with both parents--and when conflict between parents is minimal. He advocates using professional consultation and mediation to work out joint custody solutions, and keeping arrangements flexible to accommodate family changes. Warshak hopes to alter how society thinks about child custody, and he offers proposals to lawmakers and judges for revising the present system, as well as guidance to other mental-health professionals working with divorced parents. Lists and summaries abound, making his ideas crystal clear. Worthwhile reading for anyone involved in divorce and child- custody issues.