OPINION

TOBRINER, J.

Bedrich G. fled Czechoslovakia in 1968 with his two children and entered the United States as a political refugee. After Bedrich died in 1969, the juvenile court took jurisdiction over the children and placed custody with foster parents in California. Their mother, a resident of Czechoslovakia, now seeks to recover custody of her children. The juvenile court, however, ruled that the best interests of the children would be promoted by continuing their placement with the foster parents; the mother appeals from that order.

The present case is the first juvenile court custody dispute to come before us since passage of the Family Law Act in 1969 and the only reported case, to our knowledge, in which a superior court has awarded custody to a nonparent against the claim of a parent expressly found fit to care for the children. These circumstances compel us to inquire into the relationship of the Family Law Act to custody proceedings under the Juvenile Court Law. We have concluded that Civil Code section 4600 governs custody awards in juvenile court proceedings, and that under this section it is no longer essential that a court, to award custody to a nonparent, find the parent unfit to care for the child. Such an award, however, must be supported by an express finding that parental custody would be detrimental to the child and that finding must be supported by evidence showing that parental custody would actually harm the child.

We summarize briefly our resolution of the issues raised by this appeal. First, we observe that although the juvenile court failed to notify the mother of her right to appear at the 1969 jurisdictional hearing, the mother has waived that omission and consented to the jurisdiction of the court. We also confirm the ruling of the superior court granting the foster parents' standing to appear as parties in this proceeding. We cannot, however, affirm the order of the juvenile court awarding custody to the foster parents, since that order does not conform to the requirements of section 4600 The court rendered no finding that an award of custody to the mother would be detrimental to the children; its opinion, moreover, strongly suggests that the juvenile court decided the question of custody solely on the basis of the "best interests" of the children, without applying the principle that an award of custody to the parent is the preferred disposition, and that a contrary result requires a showing that such custody would be actually harmful to the child. We therefore reverse the order of the juvenile court and remand the cause to that court for further proceedings.

1. The facts.

V.G. and B.G. (hereinafter referred to as the children) were born in Czechoslovakia in 1963 and 1964, respectively, the children of the marriage of Bedrich and Vlasta G. In August 1968, shortly after Soviet troops occupied Czechoslovakia, Bedrich, their father, fled the country with his two children. Vlasta, their mother, did not consent to the children's departure nor did she know about it until she arrived home from work. The father took the children to Munich, West Germany.

The father remained in Munich for about six months. During this period he attempted to persuade his wife to join him; she, in turn, sought to convince him to return to Czechoslovakia with the children.

In March 1969, the father's mother and stepfather (hereinafter referred to as grandparents, grandfather or grandmother), residents of Yucaipa, California, sent the father funds to enable him to come to the United States. The father and children flew to California and entered the United States as political refugees. They went to live with the grandparents; the father found employment and arranged for day care for the children with neighbors, Roy and Madeline Smith. Three weeks after his arrival in California the father collapsed; a medical examination revealed terminal cancer. In June 1969, the father, who was then too weak to write, dictated a "will" to an interpreter in which he stated that the children should remain in the United States. The father died on July 8, 1969.

The mother, who was injured in an automobile accident in November 1968, was still recuperating in May 1969, when she first learned that the children's father was seriously ill. The grandparents sent her an airplane ticket but apparently failed to supply the necessary documents to secure a visa.

The probation department, informed that the father had died and that the children were staying with the Smiths, who had applied for a foster home license, scheduled a dependency hearing. The department did not orally contact the grandparents, who could not be reached because of their work schedules, but sent them notice of the dependency hearing by mail. It did not notify the mother or any agency, such as the embassy, that might reasonably be expected to forward notice to the mother.

On August 29, 1969, the minors appeared in juvenile court in response to petitions filed by the social worker. The petitions stated that: (1) the father had died in California; (2) the "mother's exact whereabouts is unknown; she is presumed living in Czechoslovakia"; and (3) the children are Czechoslovakian nationals. The court found the allegations true, adjudged the minors dependent children of the juvenile court, and placed them in the custody of the welfare department to be maintained in the home of the Smiths as their foster parents.

During the next two years the children resided with the foster parents. The matter came before the court for annual review in August 1970, but the mother received no notice of this proceeding; the court confirmed the disposition established by the August 1969 order. During this period the mother and grandmother continued to exchange correspondence, but the mother was never informed that the children were living with foster parents or that they were subject to court supervision. On September 27, 1970, the mother remarried. She continued her efforts to secure help from the Czechoslovakian Red Cross, the Brno Office for the Protection of Children, the Ministry of Foreign Affairs and the Czechoslovakian Embassy in Washington, D.C.

In December of 1970, the grandparents visited the welfare department and informed the department that they had received letters from the Czech Embassy indicating that the embassy thought the children were living with the grandparents and had engaged an attorney to institute proceedings to return the children to their mother. In re-examining the file, the social worker discovered an envelope with the mother's address on it, which apparently had been received some time earlier.

The matter again came before the court for annual review in August 1971. The court, now aware of the mother's desire to regain custody of her children, continued the case for 30 days. After further continuances, the mother appeared by counsel on November 4, 1971, acknowledged the personal and subject matter jurisdiction of the court, and requested the court to exercise that jurisdiction by transferring custody of the children to her. The court ordered that the children would be continued as dependent children of the court, in the custody of the probation officer, but to be maintained in the home of the mother.

The Czech Embassy arranged for the children to fly to Czechoslovakia on November 18, and the parties agreed that a welfare worker, the grandparents, and the foster parents would bring the children to the airport. On November 18, however, the children disappeared. The grandparents told the welfare worker "if you want to know where the kids are, watch T.V." The children and the foster parents appeared on the evening television news; the foster parents announced that they and the minors were going into hiding.

The next morning an attorney representing the foster parents filed a petition for writ of prohibition with the Court of Appeal. That court denied the petition on condition that the juvenile court vacate its order of November 4, and reopen the proceedings "for the purpose of conducting the Dispositional Hearing."

When that hearing began on February 28, 1972, the foster parents asserted that the juvenile court lacked jurisdiction because of its failure to notify the mother of the August 1969 jurisdictional hearing. The mother's counsel stipulated to the court's jurisdiction over the mother as of the 1969 hearing. The court then denied the foster parents' motion to dismiss. The foster parents petitioned for habeas corpus in the Court of Appeal, again asserting that the juvenile court lacked jurisdiction over the minors, but the Court of Appeal denied the petition.

On March 15, 1972, at the end of the dispositional hearing, the juvenile court stated orally its findings and reasoning. The court first noted that everyone involved — the mother, the foster parents, and the grandparents — were "fine people," and that the children had received proper and loving care from the grandparents and foster parents. He then expressly found that the mother was a fit parent for the children. the court, however, expressed its concern that the mother had encountered difficulties in relating to both her present and her former husband, that she displayed little warmth toward the children, and that the children had adapted to living in America and largely forgotten the Czech language.

The court concluded that "We have to weigh and balance the good and the bad in both directions and then choose that which, all in all, will be in the best interests of the children. . . . At any rate, it is the considered decision of the Court and one, I might say, that I arrived only at the tag end of the trial, that the welfare and best interests of the children require that they be continued as dependent children of the Court to be maintained at a home to be selected by the Court; in the meantime to be detained at the home of [the grandparents]." The court rendered no finding whether an award of custody to the mother would be detrimental to the children. After concluding its statement, the court entered a minute order continuing the children in the custody of the probation officer, to be maintained at the grandparents' home pending a probation study. Shortly thereafter, the court returned the children to the foster parents.

The mother appeals from the juvenile court's minute order continuing the court's jurisdiction over the children, and denying her legal and physical custody.

2. The jurisdiction of the court.

(1) The 1961 amendments to the Juvenile Court Law (Welf. Inst. Code, §§ 500-945) established a bifurcated juvenile court procedure. The court must first hear evidence on whether the minor is a person falling within the description set out in sections 600, 601, and 602, and hence subject to the jurisdiction of the juvenile court. (§ 701.) If the evidence shows the minor is not a person described by those sections, the court must dismiss the petition and discharge the minor. (§ 702.) If, on the other hand, the court determines the minor falls within the court's jurisdiction, it must enter a finding to that effect, and only then can it receive evidence respecting the proper disposition of the minor. (§ 702; see In re Gladys R. (1970) 1 Cal.3d 855, 859 [ 83 Cal.Rptr. 671, 464 P.2d 127].)

In the present case, the mother contends that the juvenile court never established jurisdiction over the minors, and thus erred in holding a dispositional hearing; furthermore, she argues, the record of that hearing uncontrovertably shows that there now exists no factual basis on which the juvenile court could assume jurisdiction over the children. Welfare and Institutions Code section 600, subdivision (a), permits the court to adjudge a minor to be a dependent child of the court if he "is in need of proper and effective parental care or control and has no parent or guardian, or has no parent or guardian willing to exercise or capable of exercising such care or control, or has no parent or guardian actually exercising such care or control." (Italics added.) As of August 29, 1969, the children's father was dead; their mother was in Czechoslovakia recovering from an auto accident; they had no legal guardian. The juvenile court therefore found the children fell under the terms of this section and adjudged them dependents of the court.

Nonetheless, the jurisdictional determination of August 29, 1969, suffers from a fatal defect. Since the interest of a parent in the companionship, care, custody, and management of his children is a compelling one, ranked among the most basic of civil rights ( Stanley v. Illinois (1972) 405 U.S. 645, 651 [31 L.Ed.2d 551, 558-559, 92 S.Ct. 1208]; Lois R. v. Superior Court (1971) 19 Cal.App.3d 895, 901 [ 97 Cal.Rptr. 158]), the state, before depriving a parent of this interest, must afford him adequate notice and an opportunity to be heard. ( In re Moilanen (1951) 104 Cal.App.2d 835, 842 [ 233 P.2d 91]; In re Spiers (1936) 15 Cal.App.2d 487, 491 [ 59 P.2d 838].) In the present matter, the probation department either knew the address of the mother, or knew that it could obtain that address from the grandparents. Yet it neither made such inquiry of the grandparents, nor exerted any effort to deliver notice to the mother through the Czech Embassy or through international organizations. Instead, presuming that the mother's whereabouts was unknown, the department eschewed reasonable efforts to find her and dispensed with any form of notice to her.

We recognize that the department, faced with the task of notifying a resident of a foreign nation whose address may be uncertain, may be called upon to use unconventional forms of notice which may not always succeed in apprising the party of his opportunity to appear (see Mullane v. Central Hanover Tr. Co. (1950) 339 U.S. 306, 315 [94 L.Ed. 865, 873-874, 70 S.Ct. 652]). But total absence of notice in any form cannot comport with the requirements of due process. (See Mullane v. Central Hanover Tr. Co., supra, 339 U.S. at pp. 314-315 [94 L.Ed. at pp. 873-874]; Guerrero v. Carleson (1973) 9 Cal.3d 808, 811 [ 109 Cal.Rptr. 201, 512 P.2d 833].)

We conclude, however, that the mother has waived her right to challenge the August 29, 1969, order establishing the jurisdiction of the juvenile court. When the mother first appeared before the court through counsel in November of 1971, she did not seek to terminate jurisdiction or challenge the validity of the 1969 order. To the contrary, she filed points and authorities asking the court to transfer custody to her, thereby impliedly recognizing the jurisdiction of the court to issue a dispositive order. When the foster parents subsequently attacked the court's jurisdiction by a motion to dismiss and by a petition for habeas corpus, the mother stipulated that the juvenile court did have personal jurisdiction over her after July 1969; she expressly waived any defect in notice. The stipulation and waiver cures any jurisdictional defect in the 1969 proceedings. (See In re Etherington (1950) 35 Cal.2d 863, 867 [ 221 P.2d 942].)

The mother further points out that the jurisdiction of the juvenile court rested upon its finding that, in August 1969, no parent was available to exercise care and control over the children, but that at the present instance she has come to the United States and is willing and capable of exercising such care and control. She contends, therefore, that the jurisdiction of the court should terminate. She urges that the decision of the Court of Appeal in In re Neal D. (1972) 23 Cal.App.3d 1045 [ 100 Cal.Rptr. 706] lends support to her contention.

In Neal D. the juvenile court, pursuant to section 600, subdivision (b), established jurisdiction on the ground that the mother's residence, a condemned dwelling, did not provide a suitable abode for the minors. Six months later the mother petitioned under section 778 to terminate jurisdiction because she had obtained a suitable home. The court, over the mother's objection, received a report from a social service worker which discussed the physical, mental, emotional, and social problems of the mother — all matters which were not considered at the original hearing — and on the basis of that report denied the petition to terminate jurisdiction.

The Court of Appeal reversed the juvenile court order. Its opinion analogized a hearing to terminate jurisdiction under section 778, the procedural setting of Neal D., to an annual review under section 729, the setting of the present case. It then stated that "section 729 contemplates a further hearing to determine whether the original jurisdictional facts continue to exist. . . . [T]he dispositional order following a hearing under section 729 is to be based upon continuing jurisdictional facts and circumstances which warranted the original order. . . . [W]here a minor . . . is readjudicated a ward for new and different reasons from those litigated in the original proceeding, a supplemental petition must be filed alleging the grounds upon which the readjudication is to be predicated. . . ." (23 Cal.App.3d at pp. 1049-1050.)

In the present case, the original basis of jurisdiction — the absence of a parent able to exercise care and control — patently no longer exists. Reviewing the possible grounds for jurisdiction under section 600, we observe that both the mother and the foster parents are available to care for the children; both parent and foster parents can provide them with a suitable home and the necessities of life; the children are not physically dangerous to the public; they are not suffering from neglect, cruelty, depravity, or physical abuse. The facts suggest no basis for jurisdiction under sections 601 or 602. Thus if a showing of a continuing basis for jurisdiction is essential for a dispositive order under section 729, as Neal D. indicated, we would be compelled to conclude that the juvenile court in the instant proceeding lacked the authority to make a dispositive order.

We believe, however, that Neal D., in requiring a continuing basis for jurisdiction, incorrectly interpreted the Juvenile Court Law. Section 607 specifies that the juvenile court "may retain jurisdiction over any person who is found to be a ward or dependent child of the juvenile court until such ward or dependent child attains the age of 21 years." Section 778, which authorizes the parent to petition to terminate the court's jurisdiction, directs the court to hear that petition only "If it appears that the best interests of the child may be promoted by the proposed . . . termination of jurisdiction." Section 729, which requires annual review of dependency cases, requires the court to advise all persons present of their right "to show cause, if they have cause, why the jurisdiction of the court over the minor should be terminated"; this section does not state the proof required to terminate jurisdiction, but by parity with section 778, the parent should be required to show that termination would be in the best interest of the child. Thus "[w]hile it was necessary at the original hearing . . . to show that the minor had no parent or guardian willing to exercise or capable of exercising such care or control in order to invoke the jurisdiction of the juvenile court, continuing jurisdiction over the minor is not dependent solely on whether a parent is capable of exercising proper and effective parental control over him but on whether the best interest of the child is served by freeing him from further supervision." ( In re Francecisco (1971) 16 Cal.App.3d 310, 314 [ 94 Cal.Rptr. 186]; see In re Adele L. (1968) 267 Cal.App.2d 397, 402 [ 73 Cal.Rptr. 76].)

In summary, we realize that the court in Neal D. sought, understandably, to emphasize the point that the state does not interfere with the parent-child relationship unless the specific conditions set out in sections 600-602 obtain, so that when such conditions no longer exist, the state supervision might logically terminate. But the Juvenile Court Law does not incorporate that mandate; it proceeds on the principle that once juvenile court jurisdiction is established, that jurisdiction continues as long as the best interests of the minor so require. As to the instant case, we therefore conclude that the mother, having waived her right to object to the establishment of jurisdiction in August 1969, is not entitled to require the county to prove such jurisdiction anew at the hearing of February-March 1972. Language to the contrary in In re Neal D., supra, is disapproved.

3. The standing of the parties.

(2) We turn briefly to the problem of the standing of the foster parents in this litigation. The superior court ruled that since the foster parents had applied for letters of guardianship, they could participate as interested parties in the juvenile court proceedings. The Court of Appeal ruled that the foster parents were not parties to the appeal, but permitted their counsel to argue the case as amicus curiae; we followed the same practice. But the unsatisfactory and ad hoc character of these rulings, and the unsettled state of the law respecting the standing in juvenile court of nonparents interested in the welfare of the minor, demonstrates the need for clarification by this court.

The fact of biological parenthood may incline an adult to feel a strong concern for the welfare of his child, but it is not an essential condition; a person who assumes the role of parent, raising the child in his own home, may in time acquire an interest in the "companionship, care, custody and management" of that child. The interest of the "de facto parent" is a substantial one, recognized by the decision of this court in Guardianship of Shannon (1933) 218 Cal. 490 [ 23 P.2d 1020] and by courts of other jurisdictions and deserving of legal protection. (See Goldstein, Freud Solnit, Beyond the Best Interests of the Child (1973) pp. 17-20.)

The status of the de facto parent received statutory sanction with enactment of the Family Law Act in 1969. Previously Civil Code section 138 distinguished only between awards of custody to parents and to nonparents; the Family Law Act, in Civil Code section 4600, added the stipulation that when an award of custody to the parent would be detrimental next in order of preference stands "the person or persons in whose home the child has been living in a wholesome and stable environment."

The juvenile court in a dispositional hearing must undertake "a judicious appraisal of all available evidence bearing on the child's best interests" including an evaluation of the relative merits of alternative custody awards. ( In re A.J. (1969) 274 Cal.App.2d 199, 202 [ 78 Cal.Rptr. 880].) The presence of de facto parents will aid the court in that endeavor; the views of such persons who have experienced close day-to-day contact with the child deserve consideration; moreover, an award of custody to such de facto parents is often among the alternate dispositions which the court must evaluate.

We conclude that de facto parents, such as the foster parents in this case, should be permitted to appear as parties in juvenile court proceedings. Their standing should not depend upon the filing of a petition for guardianship, although the filing of such petition may aid in attesting to their interest in the custody of the child; nor should their participation be restricted to the limited role of an amicus curiae; they should be permitted to appear as parties to assert and protect their own interest in the companionship, care, custody and management of the child.

4. The dispositional order.

(3a) California courts have long adhered to the principle that a court must award physical custody of a minor to a parent, if fit to exercise custody, as against a stranger. This principle, which the cases label the doctrine of parental preference, originally rested upon the theory that the right of a parent in his child was akin to that of a property owner in his chattel. ( In re Campbell (1900) 130 Cal. 380, 382 [ 62 P. 613].) To modern thinking, a far better rationale is that explained by Justice Traynor in his concurring opinion in Guardianship of Smith (1954) 42 Cal.2d 91 [ 265 P.2d 888, 37 A.L.R.2d 867]; that "the child's welfare is part of the responsibility of a fit parent" (42 Cal.2d at p. 95), and, indeed, that a parent fit to exercise custody may have a better understanding of the best interests of his child than does the juvenile court.

In applying the parental preference doctrine, the courts have required "a fairly extreme case" before finding a parent unfit to exercise custody. ( In re Raya (1967) 255 Cal.App.2d 260, 265 [ 63 Cal.Rptr. 252]; Lois R. v. Superior Court (1971) 19 Cal.App.3d 895, 901 [ 97 Cal.Rptr. 158].) Raya observes that "Although a home environment may appear deficient when measured by dominant socioeconomic standards, interposition by the powerful arm of the public authorities may lead to worse alternatives. A juvenile court may possess no magic wand to create a replacement for a home which falls short of ideal. California appellate decisions in wardship cases of the 'dependent child' variety demonstrate rather extreme cases of neglect, cruelty, or continuing exposure to immorality." (255 Cal.App.2d at p. 265; see In re A.J., supra, 274 Cal.App.2d 199, 202.)

Thus, prior to the enactment of the Family Law Act in 1969, the decisions had held that an award denying custody to the parent in favor of a nonparent could stand only if the parent had been proven to be unfit. As we shall show, with the enactment of the Family Law Act, the standard of unfitness was dropped and the Legislature created the new rule that in order to award custody of a child to a nonparent the court was required to render a finding that an award to a parent would be "detrimental to the child" and that such an award to a nonparent was "required to serve the best interests of the child."

The juvenile court in the present case rendered no finding that the award would be detrimental to the child; it proceeded, instead, upon the assumption that it could weigh and balance the merits and demerits of alternative placements free of any significant parental right. The instant case, consequently, poses the question whether the Family Law Act repudiates or modifies the doctrine of parental preference and permits a dispositional order based solely on a finding as to the "best interests" of the child.

The Family Law Act, in Civil Code section 4600 provides that "In any proceeding where there is at issue the custody of a minor child, the court may, during the pendency of the proceeding, or at any time thereafter, make such order for the custody of such child during his minority as may seem necessary or proper. If a child is of sufficient age and capacity to reason so as to form an intelligent preference as to custody, the court shall consider and give due weight to his wishes in making an award of custody or modification thereof. Custody should be awarded in the following order of preference:

"(a) To either parent according to the best interests of the child.

"(b) To the person or persons in whose home the child has been living in a wholesome and stable environment.

"(c) To any other person or persons deemed by the court to be suitable and able to provide adequate and proper care and guidance for the child.

"Before the court makes any order awarding custody to a person or persons other than a parent, without the consent of the parents, it must make a finding that an award of custody to a parent would be detrimental to the child, and the award to a nonparent is required to serve the best interests of the child. . . ." (Italics added.)

(4) We believe that Civil Code section 4600 governs the case at bar. Although the present appeal concerns a custody order under the Juvenile Court Law, this procedural setting is fortuitous; the issue of custody could as readily have been raised by an application for letters of guardianship, a writ of habeas corpus, or, had the father lived, an action for dissolution of marriage. In fact, California has at least eight separate proceedings in which custody questions can be litigated. (See Bodenheimer, The Multiplicity of Child Custody Proceedings — Problems of California Law (1971) 23 Stan.L.Rev. 703, 704-705.) There can be no question of the desirability of a uniform rule; the Legislature's specification that section 4600 applies to "any proceeding where there is at issue the custody of a minor child" demonstrates that section 4600 was enacted to fulfill that objective. (5) We turn, then, to the legislative history of section 4600 to determine the effect of that section upon the judicially established doctrine of parental preference. The present Family Law Act finds its origin in the 1966 Report of the Governor's Commission on the Family (hereafter Report). The commission recommended the enactment of a statute similar to the present section 4600, but which would have provided that "[T]he Court may award custody to persons other than the father or mother or de facto custodian if it finds that such award is required to serve the best interests of the child." (Report, p. 99.)

Explaining its refusal to require that such custody awards rest upon a finding of parental unfitness, the commission stated that "We have no intention of undermining the parents' right to the custody of their children, and we believe that the primacy of those rights must be preserved. We are convinced, however, that no useful purpose can be served by forcing a formalized finding of unfitness. The cases in which the child's best interest would require a custodial award to a third person may be rare, but are nonetheless serious. To take the most common example, if the custodial parent dies and the Court should specifically find that the child's welfare would be best served by awarding custody to the stepparent, with whom the child has been living and with whom he has formed a warm and stable relationship, should not the Court be able to so order without having to find a long-absent or minimally-interested parent judicially unfit? We believe that it should." (Report, pp. 39-40.)

Commenting on the commission's Report, Judge Lindsley of the San Diego Superior Court expressed concern that the proposed statutory language would permit a change in custody "merely because a subjective conclusion is reached that the child's interests will be better served somewhere else than with his parents and without any decision that the home of the parent would not be good for him." (Lindsley, The Family Court (1968) 5 Cal. Western L.Rev. 7, 21; see also Kay, A Family Court: The California Proposal (1968) 56 Cal.L.Rev. 1205, 1238-1239.) Sharing that concern, the Legislature amended the proposed statute to add a requirement that a court, before awarding custody to a nonparent, "make a finding that an award of custody to a parent would be detrimental to the child."

The report of the Assembly Judiciary Committee states the reasons for this amendment: "Limitation of the power of the court to award custody of children to persons other than a parent is the primary intent of the provisions in the new act relating to child custody. Effort was made to avoid a Painter v. Bannister [ 258 Iowa 1390, 140 N.W.2d 152, cert. denied, 385 U.S. 949 (1966)] situation in California. In that case, an Iowa court awarded custody to Iowa grandparents of a young boy who had been temporarily living with them with the permission of his father after the accidental death of his mother. The court disapproved of the "Bohemian" mode of living and intellectuality of the photographer father, a California resident, despite evidence that the father cared greatly for the child, was regularly employed and relatively successful, had remarried and would provide a stable environment. The court reasoned that Iowa farm life would be better for the interests of the child. . . .

"[B]efore custody can be awarded to one other than a parent, the court must specifically find that an award of custody to a parent would be detrimental to the child, and that the award to a nonparent is required to serve the best interests of the child. What is 'detrimental' has not been set forth with particularity. It is a nearly impossible task to devise detailed standards which will leave the courts sufficient flexibility to make the proper judgment in all circumstances . . . The important point is that the intent of the Legislature is that the court consider parental custody to be highly preferable. Parental custody must be clearly detrimental to the child before custody can be awarded to a nonparent." (4 Assem. J. (1969 Reg. Sess.) pp. 8060-8061.) (Italics added.)

In summary, the parental preference doctrine, as it existed before the enactment of the Family Law Act, embodied both a requirement that a custody order in favor of a nonparent rest upon a finding of parental unfitness, and the limitation that such an order would be made only in extreme cases. The enactment of section 4600 changes the former principle, and focuses attention not on the unfitness of the parent but the detriment to the child. (See Guardianship of Marino, supra, 30 Cal.App.3d 952, 958.) The Legislature did not, however, intend to disturb the judicial practice of awarding custody to nonparents in preference to parents only in unusual and extreme cases. (See Attorney's Guide to Family Law Act Practice (Cont.Ed.Bar (2d ed.) 1972) pp. 283-284.)

As enacted, section 4600 expressly recognizes that custody should be awarded to parents in preference to nonparents. As between parents, it permits the court to award custody "according to the best interests of the child," but in a dispute between a parent and a nonparent, the section imposes the additional stipulation that an award to the nonparent requires a finding that "an award of custody to a parent would be detrimental to the child." Pursuant to the language of this section, the legislative history previously discussed, and the policy of the Juvenile Court Law as set out in section 502, we conclude that section 4600 permits the juvenile court to award custody to a nonparent against the claim of a parent only upon a clear showing that such award is essential to avert harm to the child. A finding that such an award will promote the "best interests" or the "welfare" of the child will not suffice. (3b) In the present case, the trial court reasoned that it could weigh the advantages and disadvantages of an award to the mother and to the foster parents, and that a slight tipping of the scales in favor of an award to the foster parents would justify the denial to the mother of the custody of her children. As we interpret section 4600, this mode of reasoning is erroneous. Furthermore, the court made no finding that an award of custody to the mother would be detrimental to the children, although such finding is essential to sustain an order granting custody to a nonparent in preference to parental claims. ( Guardianship of Marino, supra, 30 Cal.App.3d 952, 959.) Since, as the trial court noted, the case is closely balanced, with each alternative custody award presenting both advantages and disadvantages, we find these errors prejudicial.

Both the mother and the foster parents have urged us not to remand this case to the superior court but to render a final custody decision ourselves. Unfortunately, we cannot do so. The issue of custody is one committed to the discretion of the trial court. (See §§ 725, 726.) Only in an exceptional case, in which the record so strongly supported a party's claim to custody that a denial of that claim by the trial court would constitute an abuse of discretion may an appellate court itself decide who should be granted custody; plainly the present case does not fall under that exception.

The order of the San Bernardino Superior Court in the instant proceeding, rendered March 15, 1972, is reversed, and the cause remanded for further proceedings consistent with this opinion.

Wright, C.J., Sullivan, J., Files, J., and Kaus, J.,^fn_ concurred.