The ‘foreign language effect’ (FLE) is a psycholinguistic phenomenon observed in bilingual individuals, acting as an emotional "filter" that differentiates their native language (L1) from a subsequently acquired foreign language (Pavelenko, 2005, 2008; Shanahan, 2008). This disparity influences the emotional depth of language use, with L1 being more intuitive, emotionally loaded, and context dependent (Grosjean & Li, 2013; Pavlenko, 2005). In this study, we used electrodermal activity (EDA) to measure physiological reactions to taboo and neutral words in L1 French and L2 English. Results show a language effect, with stronger reactions to taboo words in L1, consistent with a higher emotional depth of L1.