The influence of foreign-accented speech on credibility: Evidence from the illusory truth effect

Foreign-accented statements tend to be judged as less credible than native-accented statements. At the same time, the repetition of a statement makes it sound more truthful (i.e., Illusory truth effect). Here, we explore whether message credibility is affected by the accent in which the statement is produced, using the illusory truth paradigm. 20 native and 20 foreign Italian speakers uttering statements were recorded. In a between-participant design (N=60), one group of Italian participants listened the statements with a native-accented speech and another group with a foreign-accented speech. After some minutes, the same statements (Old-condition) was presented together with new statements (New-condition) and participants assessed their truthfulness. Social traits of the speaker’s voices were rated by new participants (N=109). Higher truthfulness ratings for Old compared to New sentences were observed, replicating the illusory truth effect. Critically, the effect was similar in both native- and foreign-accented speech. In the social traits evaluation, a negative bias versus foreign speakers was observed. Our results challenge that lower truthfulness ratings for foreign-accented speech are due exclusively to less processing fluency.