Maria Rodriguez challenges the Secretary's denial of Social Security child benefits for her adopted son. Lorenzo Santiago, Ms. Rodriguez's husband and the insured wage earner, became eligible for retirement insurance benefits in January 1966. In May 1975, a child was born to Ms. Rodriguez's sister. One year later, Lorenzo Santiago and Maria Rodriguez adopted the child, who was thereafter known as Antonio Santiago. It is undisputed that Antonio has lived with his adoptive parents since birth and that he is dependent upon them. The Secretary denied Ms. Rodriguez's application for benefits for Antonio on the ground that the child failed to meet the requirements of 42 U.S.C. § 402(d)(8).1

Ms. Rodriguez claims that section 402(d)(8) violates the equal protection and due process components of the fifth amendment by discriminating against adopted children who are not the natural or stepchildren of their adoptive parents and by erecting an irrebuttable presumption that such adopted children are not dependent upon their adoptive parents. She claims also that the Secretary should have applied Puerto Rico law regarding adoptions in determining Antonio's status. The district court upheld the statute and its application, and we affirm.

The challenged statutory provision creates two relevant classifications among children born after a parent becomes eligible for social security benefits. First, the statute treats natural children differently from adopted children. Second, the statute treats adopted children who are also natural children or stepchildren of their adoptive parents differently from those who are not. Neither of these distinctions involves any inherently suspect classification;2 nor do the distinctions impose a burden on the exercise of any fundamental right. The statute is therefore entitled to a strong presumption of constitutionality, which may be rebutted only by a showing that it "bears no rational relationship to a legitimate governmental interest." Frontiero v. Richardson, 411 U.S. 677, 683, 93 S. Ct. 1764, 1768, 36 L. Ed. 2d 583 (1973); Mathews v. DeCastro, 429 U.S. 181, 185, 97 S. Ct. 431, 434, 50 L. Ed. 2d 389 (1976); Weinberger v. Salfi, 422 U.S. 749, 768-74, 95 S. Ct. 2457, 2468-71, 45 L. Ed. 2d 522 (1975); Richardson v. Belcher, 404 U.S. 78, 84, 92 S. Ct. 254, 258, 30 L. Ed. 2d 231 (1971).

Every court that has addressed the question thus far has concluded that section 402(d)(8) meets this test. Brehm v. Harris, 619 F.2d 1016 (3d Cir. 1980); Clayborne v. Califano, 603 F.2d 372 (2d Cir. 1979); Stanton v. Weinberger, 502 F.2d 315 (10th Cir. 1974); Luna v. Secretary of HEW, Unempl.Ins.Rep. (CCH) P 16,195 (D.P.R.), aff'd, 588 F.2d 817 (1st Cir. 1978), app. dismissed and cert. denied, 442 U.S. 935, 99 S. Ct. 2873, 61 L. Ed. 2d 305 (1979); Johnson v. Califano, 462 F. Supp. 656 (D.Kan.1978); Williams v. Mathews, 441 F. Supp. 1045 (E.D.La.1977), aff'd, Williams v. Califano, 566 F.2d 1044 (5th Cir.), cert. denied, 439 U.S. 821, 99 S. Ct. 85, 58 L. Ed. 2d 112 (1978). We reach the same conclusion.

In providing for child's insurance benefits, Congress sought to furnish support for those who would have received support from the insured wage earner, but for his or her retirement or disability. Clayborne v. Califano, 603 F.2d at 377. At the same time, Congress sought to discourage economically motivated creation of family relationships by excluding from benefits persons whose relationships to the wage earner might not have existed in the absence of the prospect of eligibility for benefits. The Congressional purpose was clearly legitimate, and we are unable to say that Congress could not reasonably conclude that the classifications in issue here would further that purpose. Congress could believe that couples who would not bear a child for the purpose of gaining additional benefits might adopt a child, particularly the child of a friend or relative, with the prospect of conferring eligibility for benefits on the child as at least partial motivation. Clayborne v. Califano, 603 F.2d at 378 n.14. Similarly, Congress could reasonably believe that adoption of a child who is the adoptive parent's natural or stepchild would be less likely to be motivated by the prospect of benefits than would adoption of a child who does not already have such a relationship with the adoptive parent. Clayborne v. Califano, 603 F.2d at 378.

Rodriguez argues that no evidence has been offered to show that "anyone actually would or could adopt merely to qualify for child benefits." But the burden is on her to demonstrate that the statute is irrational; Congress need not provide empirical evidence for its legislative judgments. Vance v. Bradley, 440 U.S. 93, 110-11, 99 S. Ct. 939, 950, 59 L. Ed. 2d 171 (1979); Hughes v. Alexandria Scrap Corp., 426 U.S. 794, 812, 96 S. Ct. 2488, 2499, 49 L. Ed. 2d 220 (1976). She relies on the strict supervision of adoptions provided by state courts and child welfare agencies, arguing that this oversight prevents improperly motivated adoptions. But Congress could have believed that, in some cases, state officials might find that a child's interests would be served by an adoption that would improve the child's economic well-being by rendering him or her eligible for federal benefits. Adoption under such circumstances, while perfectly proper and not in any sense fraudulent, would circumvent Congress' intention to limit benefits to those who would otherwise have received support from the insured wage earner. Brehm v. Harris, 619 F.2d at 1020-21; see Clayborne v. Califano, 603 F.2d at 378 n.12.

Rodriguez also cites 42 U.S.C. § 416(c)(4), which makes a surviving spouse eligible for benefits, notwithstanding short duration of the marriage, if the couple had adopted a child. Based on this provision, Rodriguez argues that Congress has conclusively presumed the good faith of every adoption. As the court held in Clayborne v. Califano, 603 F.2d at 379 n.16, this argument mistakes the purpose of section 416(c)(4); in the context of marriages of short duration, Congress viewed adoption of a child as evidence that the marriage was entered into for reasons other than the expectation of survivor's benefits on the early death of a spouse. That judgment has no necessary bearing on Congressional views of the possible motives of adoptive parents applying for child's benefits.

Ms. Rodriguez next argues that the statute violates due process by creating an irrebuttable presumption that children in the excluded category are not dependent on their adoptive parents. Citing Stanley v. Illinois, 405 U.S. 645, 92 S. Ct. 1208, 31 L. Ed. 2d 551 (1972), and Vlandis v. Kline, 412 U.S. 441, 93 S. Ct. 2230, 37 L. Ed. 2d 63 (1973), she argues that each child is entitled to an opportunity to prove his or her dependence. The Supreme Court considered and rejected a nearly identical argument with respect to eligibility requirements for social security benefits in Weinberger v. Salfi, 422 U.S. 749, 768-74, 95 S. Ct. 2457, 2468-71, 45 L. Ed. 2d 522 (1975), and that case is controlling here. Like the statutory classification in that case, the provision in issue here establishes objective criteria for eligibility, criteria which we believe to be rationally related to a legitimate legislative goal; and each applicant is free to present evidence that he or she meets these criteria. No constitutionally protected liberty interest is affected, as in Stanley, nor does the statute purport to grant benefits to all persons in a subjectively defined category, but then preclude proof of one's membership in that category, as in Vlandis. Weinberger v. Salfi, 422 U.S. at 771-72, 95 S.Ct. at 2469-70. As in Salfi, the statutory criteria applied here are undoubtedly to some degree both overinclusive and underinclusive, allowing benefits for some children whose adoptions are motivated by the prospect of eligibility, while excluding others who were adopted entirely for other reasons. Salfi, 422 U.S. at 776, 95 S.Ct. at 2472. Nevertheless, Congress is entitled to employ a generalized rule, despite its imperfection, when it "can rationally conclude ... that the difficulties of individual determinations outweigh the marginal increments in the precise effectuation of congressional concern which they might be expected to produce." Salfi, 422 U.S. at 785, 95 S.Ct. at 2476; Clayborne v. Califano, 603 F.2d at 380; Williams v. Mathews, 441 F. Supp. at 1049.

Ms. Rodriguez asserts finally that in determining the status of her son the Secretary should have applied the law of Puerto Rico, which she characterizes as treating adopted children more favorably than the laws of the mainland states do. This argument needs no more response than a citation to the supremacy clause, Art. 6, cl. 2 of the United States Constitution. Section 402(d)(8) prescribes the treatment of adopted children for purposes of child's benefits, and the federal statute must prevail, despite any conflict with Puerto Rico law.3 Rodriguez offers an extensive discussion of the social and cultural role of adoption in Puerto Rico society, arguing that the legislative scheme is particularly arbitrary when applied in that context. It might be true that the statutory classification is less well-suited to its purpose when applied in Puerto Rico or to specific cultural groups elsewhere within our diverse society than when applied to the nation as a whole. This observation would not, however, deprive the statute of any rational relationship to its legitimate objectives.

Affirmed.