The U.S. Supreme Court has found that the right to marry is a constitutionally protected right. That right is restricted, however, by state incest statutes which impede marriage between adults by making some choices of a marriage partner illegal. The constitutional validity of modern state incest statutes is difficult to analyze because of shifting definitions, reflexive fears, ambivalent attitudes, and underlying facile generalizations.
The mere word "incest" triggers strong feelings of revulsion in most people. Therefore, any a priori labeling of a marriage as incestuous tends to preclude objective thought about the permissibility of the particular form of the marriage prohibition at issue. Such revulsion stems largely from the confusion of incest with sexual abuse of children. This confusion is not limited to the general public, but extends to the courts as well.
The incest motif itself persists as a tradition. Alleged public horror combined with obvious fascination for the theme extends in an unbroken line from the myths of preliterate peoples to contemporary literature. Any examination of contemporary incest statutes as a limitation on the right to marry must be sensitive to the historically ambivalent reactions to acts in contravention of the prohibition.
Finally, myths and half-truths about the genetic effects of incestuous matings on the offspring represent another impediment to an analysis of the constitutional validity of contemporary incest statutes as marriage prohibitions. Although directly contradicted by current scientific knowledge of genetic inheritance, common knowledge continues to teach that incestuous unions cause mentally and/or physically defective offspring.
Once one recognizes these analytical difficulties—reflexive fears, shifting definitions of incest itself, ambivalent attitudes, and facile underlying generalizations—one can begin to rationally evaluate the validity of state incest statutes in the light of the constitutional right to marry. After making such an analysis, this author has concluded that neither the civil marriage bar nor the criminal bar against incestuous acts serves any valid purpose which cannot be better served by statutes which do not impinge on the constitutional right to marry.
Carolyn S. Bratt, Incest Statutes and the Fundamental Right of Marriage: Is Oedipus Free to Marry?, 18 Fam. L.Q. 257 (1984).