The debate over evolution instruction in public schools has become one of the most important and contentious debates in America. At the heart of that debate is the controversy over the use of evolution disclaimers, statements that challenge the veracity of evolution as an explanation of human origins. In evaluating the constitutionality of these disclaimers under the Establishment Clause, courts have applied a variety of different standards, including the three-part test articulated by the Supreme Court in Lemon v. Kurtzman. These standards, however, all fail to adequately reflect the proper scope of the Establishment Clause by being either overbroad, under-inclusive, or both. This problem is magnified by the recent development of disclaimers that are facially neutral with regard to religion. The emergence of facially neutral disclaimers necessitates a new standard that is free of the shortcomings of preexisting doctrine while offering a consistent and reliable method of evaluating future generations of disclaimers under the Establishment Clause. This Article proposes such a standard, modeled on the disparate impact test used to evaluate facially neutral discriminatory statutes under the Fifth and Fourteenth Amendments. It concludes that the disparate impact model constitutes a stable, objective approach that not only alleviates the weaknesses of existing Establishment Clause doctrine, but brings needed structure to an active and important area of law.