The Dillingham Flaw is a term coined by U.S. sociologist Vincent N. Parrillo to identify a centuries-old phenomenon of faulty logic when nativists misinterpret and react negatively to the presence of immigrants in their midst.
The term draws its name from a special commission created in 1907 by President Theodore Roosevelt to look into the “immigration problem.” Named after its chairman, U.S. Senator William P. Dillingham of Vermont, the Dillingham Commission over a 4-year period listened to testimony from civic leaders, educators, social scientists, and social workers and made on-site visits to Ellis Island and New York City’s Lower East Side. In 1911, the Commission issued a 41-volume report of its findings. Unfortunately, the report was flawed in its interpretation of the data that the Commission had so tirelessly collected. The Commission erred in its use of simplistic categories for diverse immigrant groups and in making an unfair comparison of “old” and “new” immigrants, despite the changed structural conditions and longer time interval that previous immigrants had to assimilate and to achieve some measure of economic security.
Quite simply then, the term Dillingham Flaw refers to inaccurate comparisons of immigrant groups based on simplistic categorizations and anachronistic observations. Parrillo argued that this erroneous thinking can occur in assessments of the past, present, or future.
Applying modern classifications or sensibilities to a time when they did not exist, or, if they did, had a different form or meaning, is one version of the Dillingham Flaw. For example, today’s term British refers collectively to the people of the United Kingdom (the English, Welsh, Scots, and Scots-Irish). However, in the 18th century, British had the much narrower meaning for only the English, and for good reason. The English, Welsh, Scots, and Scots-Irish may have all been English-speaking, but significant cultural and religious differences existed among them and they did not view each other as “similar.” Anyone who presumes that the colonial British, even just the colonial English, were a single cohesive entity, and thus the 13 English colonies were homogeneous, would fall victim to the Dillingham Flaw.