Opinion
REYNOSO, J.No human bond is cemented with greater strength than that of parent and child. We address the claims of two who assert they are the father of a daughter. One was the mother’s husband; he raised, loved and nurtured the child until temporarily prevented from doing so after a divorce. The second claimant contends he is the natural father, has since *358married the mother and now lives with her and the child. By this triangular litigation each claimant seeks to be declared the legal father; the child, too, seeks a determination.
Evidence Code section 621 declares the presumption that “. . . the issue of a wife cohabiting with her husband ... is presumed to be a child of the marriage. ”1 In conformity with the statute, the trial court entered summary judgment in favor of the defendant below, Ronald W. Plaintiffs Donald R. and Michelle W., a minor, appeal challenging the constitutionality of the statute as applied to them. As will appear below, we hold that as applied to plaintiffs the statutory presumption violates neither the due process nor equal protection clauses of the California or United States Constitutions.
I
Defendants Ronald and Judith W. were married on May 7, 1965, and lived together as husband and wife until their separation approximately 12 years later. Judith gave birth to two daughters, Tamara and Michelle, who were raised as the children of that marriage. During the marriage to Judith, Ronald W. provided the necessary support for the children. As the father of Tamara and Michelle, he tended, nurtured and loved them and received affection from them. Through their daily interchanges with Ronald and Judith, Tamara and Michelle were provided with the security, as well as the restraints, they needed for their growth and development.
Donald R., the second claimant to the paternity of Michelle, met Judith in 1973. Donald R. and Judith began having sexual relations in that year, although Judith and Ronald W. were married and living together. On October 24, 1974, Judith gave birth to Michelle. Donald R. did not claim paternity at the time of birth nor thereafter for four years while Judith and Ronald W. remained married and continued to live together. Donald R. *359asserted no claim nor accepted any responsibility. Throughout that time, without objection from Donald R., the obligation of parenting was fulfilled by Ronald W.
When Ronald and Judith W. separated they executed a marriage settlement agreement; Ronald was granted custody of Tamara, Michelle’s sister, and Judith custody of Michelle, by then nearly five years of age. The issue of paternity was not raised. Ronald’s obligation to provide child support for Michelle was also not at issue; it was agreed upon.
Following the dissolution of their marriage, Ronald W. regularly and continually exercised his visitation rights with Michelle. In November 1980, when Donald R. married Judith, Ronald W. was refused further visitation. That right was restored when he threatened court action to enforce the settlement agreement. Since Judith’s marriage to Donald R., Michelle has lived in Donald R.’s home and he has held her out to be his natural child.
In March 1981, this action to establish paternity was brought by Donald R. and Michelle, age six, through her guardian ad litem. Upon the uncontradicted facts that Ronald W. and Judith were living together as a married couple for nine years before Michelle’s birth and that Ronald W. was neither impotent nor sterile, the trial court applied the presumption of section 621 and established that Ronald W. is the father of Michelle. Plaintiffs appeal.
II
The presumption of paternity established by section 621 is limited. The following prerequisites must be satisfied: first, the child’s mother must be married; second, the mother must be cohabiting with her husband; third, the husband must be neither impotent nor sterile; fourth, two years must have passed since the birth of the child and during those two years the husband—or the mother in conjunction with the putative father—must have failed to rebut the presumption in court.
Plaintiffs assert alternative grounds for holding section 621 unconstitutional. First, section 621 prevents them from establishing the biological parent-child relationship in a court of law, thus depriving them of a liberty interest protected by the due process clause. Second, the gender-based classification of the statute which accords the natural father fewer procedural protections than the married natural mother violates the equal protection *360guarantee of the California and United States Constitutions.2 In addition, they argue that the classifications in the statute deny them a fundamental right and thus the law should be strictly scrutinized.
A. Due Process Claims
We review two interests, that of the child and that of the alleged natural father. As to plaintiff Donald R., we hold that the statute is constitutional as applied. No due process violation can be found in applying the presumption to the facts of this case. Our conclusion is based upon a weighing of the competing private and public interests. We find that the public interest in protecting the family unit and promoting familial stability outweighs Donald R.’s interest.
1. The Putative Father’s Claim
Does the application of the presumption of section 621 violate Donald R.’s due process rights? We have held that the issue of whether section 621 adequately protects a putative father’s interests “must be resolved by weighing the competing private and state interests. ” (In re Lisa R. (1975) 13 Cal.3d 636, 648 [119 Cal.Rptr. 475, 532 P.2d 123, 90 A.L.R.3d 1017], cert. den. (1975) 421 U.S. 1014 [44 L.Ed.2d 682, 95 S.Ct. 2421], rehg. den. (1975) 423 U.S. 885 [46 L.Ed.2d 116, 96 S.Ct. 159].) In Board of Regents v. Roth (1972) 408 U.S. 564, 570 [33 L.Ed.2d 548, 570, 92 S.Ct. 2701], the high court explained that “a weighing process has long been a part of any determination of the form of hearing required in particular situations. ...” (Italics in original.)
The United States Supreme Court has scrutinized, under the due process clause, state laws limiting a natural father’s relationship with his illegitimate offspring in three seminal cases,3 Stanley v. Illinois (1971) 405 U.S. 645 [31 L.Ed.2d 551, 92 S.Ct. 1208], Quilloin v. Walcott (1978) 434 U.S. 246 [54 L.Ed.2d 511, 98 S.Ct. 549], rehg. den. (1978) 435 U.S. 918 [55 *361L.Ed.2d 511, 98 S.Ct. 1477], and most recently in Lehr v. Robertson (1983) 463 U.S. 248 [77 L.Ed.2d 614, 103 S.Ct. 2985].
In Stanley, an unwed father lost custody of his three children upon the death of the children’s unwed mother. The father, Stanley, had lived with the children and their mother since their birth and they were summarily taken and placed with court-appointed guardians without any prior hearing. This deprivation was found to violate the due process clause of the Fourteenth Amendment. Justice Powell, writing for the court, concluded that Illinois, “insists on presuming rather than proving Stanley’s unfitness solely because it is more convenient to presume than to prove. Under the Due Process Clause that advantage is insufficient to justify refusing a father a hearing when the issue at stake is the dismemberment of his family.” (405 U.S., at p. 658 [31 L.Ed.2d at p. 562].) Thus, Illinois could not automatically destroy the Stanley family and uproot the children without first providing the father with the opportunity to be heard on the issue of parental fitness.
The limits on a putative father’s due process rights were addressed in Quilloin v. Walcott, supra, 434 U.S. 246, where the Supreme Court held that a Georgia statute which denied an unwed father the right to veto an adoption of his illegitimate child did not violate the due process clause. The father in that case only sought to claim paternity after the mother and her new husband had initiated adoption proceedings. The court held that the denial of the father’s legitimation petition—found by the trial court to be in the child’s best interest—did not violate the due process clause.
Finally, the court most recently addressed this issue in Lehr v. Robertson, supra, 463 U.S. 248. Lehr, the putative father, sought to invalidate an adoption order granted in favor of the biological mother and her husband. The child was already two years old at the time and the father “never had any significant custodial, personal, or financial relationship with [the child], and he did not seek to establish a legal tie until she was two years old.” (Id., at p. 262 [77 L.Ed.2d at p. 627], fn. omitted.)
This court has examined the conclusive presumption of paternity in Lisa R., supra, 13 Cal.3d 636, where a putative father sought to continue the parent-child relationship he had established with his daughter. In Lisa R., although the minor child was presumed to be legitimate, both of her parents were deceased and the child was being adjudicated a dependent of the juvenile court. With adoption proceedings by foster parents pending, Lisa’s putative father sought to prove his paternity and obtain visitation rights. Following the United States Supreme Court’s decision in Stanley v. Illinois, *362supra, 405 U.S. 645, we held that the Evidence Code’s preclusion of proof of paternity offended the constitutional guarantee of due process of law.
The difference between the state-threatened dissolution and termination of a developed parent-child relationship in Stanley and Lisa R. and the denial of a legal determination of paternity in the case at bench is clear and significant. As we recently noted, “In both Stanley and Lisa R., the putative fathers were seeking to establish their legal relationship with children who otherwise had no parents and were wards of the state.” (Estate of Cornelious (1984) 35 Cal.3d 461, 466 [198 Cal.Rptr. 543, 674 P.2d 245], app. dism. (1984) 466 U.S. 967 [80 L.Ed.2d 812, 104 S.Ct. 2337].)
This is not a case where the state has attempted to intervene or to prevent the establishment of a relationship between putative father and child.4 Rather, Donald R. seeks a determination that he is Michelle’s “legal” father, notwithstanding the established and continuing emotional and financial father-daughter relationship between Michelle and Ronald.5 Accordingly, we conclude that Donald’s abstract interest in establishing paternity is not as weighty as the interests of the fathers in Stanley and Lisa R.
We turn to the interests of the state. Numerous policy considerations have been cited in favor of a conclusive presumption of paternity, including certain social policies upholding the integrity of the family (Kusior v. Silver (1960) 54 Cal.2d 603, 619 [7 Cal.Rptr. 129, 354 P.2d 657]), and protecting the child’s welfare (In re Lisa R., supra, 13 Cal.3d at pp. 649-650).
Thus, section 621 does not purport to factually determine the biological paternity of a child. (Kusior v. Silver, supra, 54 Cal.2d at p. 619.) We note that, as stated by the United States Supreme Court, “[t]he actions of judges neither create nor sever genetic bonds.” (Lehr v. Robertson, supra, 463 *363U.S. at p. 261 [77 L.Ed.2d at p. 626].) The interests noted above apply to the facts of the case at bench. Here, Donald R.’s private interest in establishing a biological relationship in a court of law is overridden by the substantial state interests in familial stability and the welfare of the child. Accordingly, the application of section 621 to the instant case comported with the requirement of due process of law.
2. The Child’s Claim
The second interest to consider in this case, the interest of Michelle in a legal determination of who her biological father is, has been treated by the other litigants as an appendage to the rights of the putative father. The guardian ad litem for Michelle is a family friend of Donald and Judith R. Michelle is represented by the same attorney as Donald R. and their interests have been continually asserted as being consistent with each other. Our concern is that Michelle is not the real actor behind this “child” paternity suit and that she may be asserting a right which may or may not be in her best interests.6 We are not convinced under the circumstances of this case, that Michelle’s rights are greater than those afforded to Donald R.
In Estate of Cornelious, supra, 35 Cal. 3d 461, we held that the guarantee of due process of law was not offended when a child was precluded from proving paternity by the operation of section 621. In Estate of Cornelious, as in the case at bench, we apply a balancing test to resolve an as-applied challenge to the statute in question. (35 Cal.3d at p. 467.) Because Michelle’s rights have not been argued to be separate from Donald R.’s we cannot conclude that her interest in establishing paternity outweighs the state’s interest in preserving and protecting the developed parent-child and sibling relationships which give young children social and emotional strength and stability. Given the facts that Michelle has a legal father and that he opposes this attempt to have Donald R. declared the biological father, we are unpersuaded that a judicial juggling of Michelle’s family relationships is warranted by her abstract interest in establishing paternity.
We reject plaintiffs’ suggestion that section 621 as applied to Michelle is constitutionally defective pursuant to the authority of Vlandis v. Klein (1973) 412 U.S. 441 [37 L.Ed.2d 63, 93 S.Ct. 2230]. In Vlandis the United *364States Supreme Court invalidated a permanent and irrebuttable presumption that students who were nonresidents when they applied to attend state universities remained nonresidents for purposes of assessing fees and tuition.7 While Vlandis involved a purported factual determination of residency, section 621 does not purport to determine biological paternity. Rather, it is “in actuality a substantive rule of law” designed to further public policies. (Kusior v. Silver, supra, 54 Cal.2d 603, at p. 619.)
Furthermore, because we apply the balancing test utilized in Estate of Cornelious, we cannot conclude that the presumption of section 621 is necessarily irrebuttable. Simply because Donald R. and Michelle are unable to rebut the presumption does not mean that we interpret section 621 to be a “conclusive and unchangeable presumption. ” (Vlandis v. Klein, supra, 412 U.S. at p. 443 [37 L.Ed.2d at p. 66].) Rather, we merely conclude that the denial of Michelle’s motion for blood tests was justified because the state interests outweighed her abstract interest in vindicating true parentage.
Michelle is not being threatened with termination of her association with Donald R. She is not even being prevented from obtaining information as to who her biological father is. As stated by the United States Supreme Court, the extent to which due process must be afforded an individual “is influenced by the extent to which he may be ‘condemned to suffer grievous loss.’” (Goldberg v. Kelly (1970) 397 U.S. 254, 262-263 [25 L.Ed.2d 287, 296, 90 S.Ct. 1011].) We cannot say that denying Michelle the opportunity to present blood test evidence in a court of law violates the guarantee of due process of law.
B. Equal Protection
The guarantee of equal protection ensures that “no person or class of persons shall be denied the same protection of the laws which is enjoyed by other persons or classes in like circumstances . . . .” (People v. Romo (1975) 14 Cal.3d 189, 196 [121 Cal.Rptr. 111, 534 P.2d 1015].) Specifically, a sovereign may not subject men and women to disparate treatment where there is no substantial relationship between the classification and an important governmental purpose. (Reed v. Reed (1971) 404 U.S. 71, 76 [30 L.Ed.2d 225, 229, 92 S.Ct. 251]; Craig v. Boren (1976) 429 U.S. 190, *365197 [50 L.Ed.2d 397, 407, 97 S.Ct. 451], rehg. den. (1977) 429 U.S. 1124 [51 L.Ed.2d 574, 97 S.Ct. 1161].)
Section 621 allows the natural mother of the child to bring a suit to rebut the presumption that her husband is the child’s father. Plaintiffs claim that this constitutes an impermissible gender-based distinction because the putative father is not allowed to rebut the presumption.8 We disagree.
Subdivision (d) of section 621 states: “The notice of motion for blood tests under subdivision (b) may be raised by the mother of the child not later than two years from the date of birth if the child’s biological father has filed an affidavit with the court acknowledging paternity of the child.” We note that the plain word of the statute indicates that the rights of the natural married mother and the natural unwed father are conditioned upon each other.
Thus, this case is distinguishable from Caban v. Mohammed, supra, 441 U.S. 380. In that case the Supreme Court invalidated a statutory scheme under which only unwed mothers—and not unwed fathers—received hearings prior to a termination of child custody.
In Caban, one parent had an absolute unconditional right and the other parent had absolutely none. In our due process analysis, we have declined to interpret section 621 as an absolute bar to all suits to establish paternity by either the putative father or the presumed legitimate child. Rather, we have applied the balancing test analysis of Lisa R. and Estate of Cornelious. In contrast to Caban, although Donald R. and Michelle are not able to rebut the presumption under the facts of this case, this does not mean that all putative fathers and all presumed legitimate children are barred in all cases. Thus, we fail to find that the statutory scheme, as interpreted by the courts and as applied to plaintiffs’ case, violates the guarantee of equal protection of the laws.
The judgment is affirmed.
Mosk, J., Kaus, J., Broussard, J., and Grodin, J., concurred.
All further statutory references are to the Evidence Code. Section 621, subdivision (a) states in full that: “(a) Except as provided in subdivision (b), the issue of a wife cohabiting with her husband, who is not impotent or sterile, is conclusively presumed to be a child of the marriage.”
Subdivision (b) allows rebuttal of the presumption of subdivision (a) by blood test evidence. Subdivisions (c) and (d) provide that such evidence must be presented within two years of the child’s birth.
Plaintiffs do not challenge and we do not now address any question regarding the adequacy of the two-year statute of limitations, although we note that the United States Supreme Court decision in Mills v. Habluetzel (1982) 456 U.S. 91 [71 L.Ed.2d 770, 102 S.Ct. 1549] suggests that this raises due process concerns.
We note that the version of section 621 which was in effect in 1981, the date plaintiffs filed their action, differs somewhat from that now in effect. Because plaintiffs challenge— and the appellate court analyzed—the present version of section 621, our decision, too, is based on the present statute.
The Fourteenth Amendment provides that no state shall “deprive any person of life, liberty, or property, without due process of law; nor deny any person within its jurisdiction the equal protection of the laws.” A similar provision is contained in the California Constitution, article I, section 7, subdivision (a) which states that “[a] person may not be deprived of life, liberty, or property without due process of law or denied equal protection of the laws. ...”
Although we deny plaintiffs’ claims under both Constitutions, we do not hold that the provisions are identical in scope and purpose in all cases.
The issue was also raised in Caban v. Mohammed (1979) 441 U.S. 380 [60 L.Ed.2d 297, 99 S.Ct. 1760]. Because that case was decided on equal protection grounds, the court expressed no view on the due process challenge. (Id., at p. 394, fn. 16 [60 L.Ed.2d at p. 308].)
We leave open the question of the validity of section 621 as applied to such situations or to termination situations for a case in which the issue is squarely presented.
Ronald W. argues, without citation to authority, that in enacting section 621 the Legislature sought to prevent children from being stigmatized as “illegitimate.” Even assuming that this argument is correct, this state’s subsequent adoption of the “Uniform Parentage Act” (Civ. Code, § 7000 et seq., added by Stats. 1975, ch. 1244, § 11, pp. 3196-3204) has rendered such a consideration to be without any legal effect. The act, approved in 1973 by the National Conference of Commissioners on Uniform State Laws (see Uniform Parentage Act, Comrs. Prefatory Note, 9A U.L.A. (Master ed. 1979) pp. 579-582), “makes a revolutionary change in the law by abolishing the incidents of illegitimacy and establishing legal equality of children without regard to the marital status of their parents” (6 Witkin, Summary of Cal. Law (8th ed., 1984 supp.) Parent and Child, § 242A, p. 326). As now provided by Civil Code section 7002, “[t]he parent and child relationship extends equally to every child and to every parent, regardless of the marital status of the parents.” Accordingly, we reject Ronald’s argument that the “stigma” of illegitimacy should be considered in determining the constitutionality of section 621.
The possibility exists for a conflict between a child’s interest and that of the putative father. For example, it has been noted that “[u]nlike adults, children have no psychological conception of relationship by blood-tie until quite late in their development. For the biological parents, the facts of having engendered, borne, or given birth to a child produce an understandable sense of preparedness for proprietorship and possessiveness. These considerations carry no weight with children who are emotionally unaware of events leading to their births.” (Goldstein et al., Beyond the Best Interests of the Child (1973) at p. 12.)
We also reject plaintiffs’ argument that Vlandis requires invalidation of a conclusive presumption whenever there is a “reasonable alternative means” of proving the presumed fact. In Vlandis the existence of other methods of proving residency was one factor in the Supreme Court’s analysis. In invalidating the statutory presumption, the court discussed the state’s purposes for the presumption and determined that those were not served by applying the presumption to the case before it. (412 U.S. 441, at pp. 448-452 [37 L.Ed.2d 63, 69-71, 93 S.Ct. 2230].)
MichelIe’s guardian and Donald R. also argue that putative fathers are denied a fundamental right to establish a parent-child relationship. As discussed in our due process analysis of this case, we fail to find such a deprivation. The association between Donald R. and Michelle is already enjoyed and the state does not seek its disruption or its termination.