Beyond the foreign language effect: unravelling the impact of l2 proficiency on rationality

This study investigated the impact of reading statements in a second language (L2) versus the first language (L1) on core knowledge confusion (CKC), superstition, and conspiracy beliefs. Previous research on the Foreign Language Effect (FLE) suggests that using an L2 elicits lessintense emotional reactions, promotes rational decision-making, reduces risk aversion, causality bias and superstition alters the perception of dishonesty and crime, and increasestolerance of ambiguity. Our results do not support the expected FLE and found instead aneffect of L2 proficiency: Participants with lower proficiency exhibited more CKC, were moresuperstitious and believed more in conspiracy theories, regardless of whether they were testedin L1 or L2. The study emphasises the importance of considering L2 proficiency wheninvestigating the effect of language on decision-making and judgements: It-or relatedfactors-may influence how material is judged, contributing to the FLE, or even creating anartificial effect.