The Case for Banning Cousin Marriage

This article presents the universal case for banning cousin marriage regardless of jurisdiction or culture. It is intended both as a resource—the relevant facts and opposing arguments will be set out plainly for reference purposes—and a legal argument which seeks to demonstrate that the weight of evidence concerning this poorly understood practice supports outright prohibition. Accordingly, the article is divided into five parts. The introduction briefly outlines the key controversies within the field of comparative consanguinity law and signposts the way forward. There follows an examination of the modern definition and distribution of cousin marriage to establish its current prevalence and key trends, before an explanation of the consequences resulting from its practice and factors contributing to consanguineous preferences. The article then takes an analytical turn to assess five common arguments against banning cousin marriage proceeding from, respectively, (i) human rights, (ii) prejudice, (iii) custom, (iv) choice, and (v) proportionality. Having factored in the relevant medical, social, historical, and geopolitical evidence throughout, it concludes by arguing the case in favour of a ban with specific proposals as to its justification and recommended scope, substance, and implementation.