Is foreign accented speech less credible? Evidence from the IllusoryTruth Effect

Foreign-accented (FA) statements are judged as less credible than native-accented (NA) statements. At the same time, the repetition of a statement makes it sound more truthful (Illusory-truth effect). Here, we explore the interaction between these two phenomena in a between-participant design. 10 native-Italian (Exp.1) and 10 foreign-Italian (Exp.2) speakers uttering 80 statements were recorded. Speakers’ voices were rated by 109 participants on several social dimensions (e.g. status, desirability). In the main experiment, 60 Italian-speakers (30 per experiment) listened 40 unknown-sentences. After few minutes, the same set-of-sentences (Old-condition) were presented together with a new set of 40 sentences (New-condition) and participants assessed the truthfulness of the statements on a 6-point-scale. Higher truthfulness rates for Old compared to New sentences were observed, replicating the illusory-truth effect. There was no interaction between the experiments, suggesting a similar amount of illusory-truth effect for FA and NA statements. No modulations of the social dimensions of the speaker's voices were observed. Overall, our results challenge previous results on lower truthfulness rates for foreign-accented speech.