Does a Foreign Language Make Us More Rational, or Just Less Capable of Moral Thought?

Abstract Bilinguals often choose more utilitarian options when reasoning in a second language. This pattern is commonly read as improved rationality through emotional distance. I argue the better explanation is processing cost and reduced expressive capacity: these nudge people toward simpler, outcome-counting heuristics and thinner deontic justification. The critique has prior defenders, who drew on the somatic marker hypothesis to show that native-language reasoning tends to produce more ethical choices. The present paper extends that line of argument in a specific direction. Model-based decomposition studies show that the foreign-language effect reduces both deontological and utilitarian inclinations simultaneously; the apparent utilitarian shift arises because deontological sensitivity drops further in high-conflict dilemmas, not because utilitarian motivation increases. This dissociation is the empirical backbone my justificatory thinning account requires. Emotions here are not mere noise but epistemic inputs that supply moral concepts and appraisals; their attenuation under expressive constraint matters for how decisions are justified, not only chosen. I propose a processing-cost mechanism with testable predictions by proficiency and dilemma type, a five-item coding scheme for justificatory texture, and practical safeguards for multilingual deliberation – including native-language stages at key decision points, slower pacing with interpreters, and records that separate outcomes from justifications.