Abstract

This Article examines the role that the incest taboo has played in slippery slope rhetoric pertaining to same-sex marriage specifically, and non-normative family arrangements more generally, and argues that the law must reappraise the extent to which disgust, rather than reasoned argument, sustains laws governing sexual and familial choice. It takes issue with the claim that discussion of the taboo has led to its erosion, and contends that it has remained a powerful symbol of non-normative sexuality that sits at the bottom of the slippery slope of sexual deviance. While often dismissed as mere rhetoric, the incest/same-sex relations analogy has been a strategic way to provoke disgust against otherwise consensual relationships. To explain why the taboo has persisted over time as a point of comparison to any non-normative family arrangement (interracial marriage, same-sex marriage), it maintains that incest, more than any other sexual taboo, represents an archetypal form of disgust and boundary violation. This theory of incest as a core symbol of disgust looks to other disciplines, including political theory, anthropology, and moral psychology, that have described disgust in similar terms, namely, as a mechanism triggered in response to any perceived instance of boundary violation. After situating the taboo within this theoretical framework, this Article explores more fully how, and why, the law has relied on the taboo to discriminate against consensual sexual relationships, most notably same-sex relations. It concludes by suggesting ways in which the law might turn away from the taboo and embrace other models that conceive of familial and sexual relationships in more expansive and less disgust-driven ways.