This article applies a constructivist perspective to the persistent transatlantic divergence over the regulation of genetically modified foods and crops. Political economy and institutionalism have so far dominated the literature. Notwithstanding their important insights, to achieve a better understanding of the nature and depth of transatlantic regulatory divergence, one must also study prevalent cultural values and identity-related public concerns regarding food and agriculture. These factors can be identified in public opinion trends and have fuelled resistance in Europe, while contributing to relative regulatory stability in the US. By conceptualizing cultural contexts as catalytic structures, the article also differs from more explicitly discursive accounts of political mobilization. Ultimately, however, an analysis of the cultural politics of agricultural biotechnology relies not only on the influence of pre-existing values and identities, but also takes account of the strategies (and material or other power resources) of political agents.