Do Accents Speak Louder Than Words? Perceptions of Linguistic Speech Characteristics on Deception Detection

Using videotaped interviews of beginner, intermediate, and native English speakers, we examined whether observers’ perceptions of linguistic measures of accentedness, temporal fluency, lexicogrammar, and comprehensibility influenced their deception detection. We found that observers could detect differences in speech characteristics between proficiency levels, and that they were less able to detect deception among beginner speakers compared to intermediate and native speakers. Beginner speakers were also afforded more of a truth bias compared to intermediate, but not native speakers. Interestingly, observers’ backgrounds, including prior exposure to non-native speech, did not influence their judgments. Rather, observers’ discrimination and response bias appeared to be most affected by speakers’ fluency and comprehensibility, respectively. This study is one of the first to separate and directly compare perceptions of linguistic characteristics and their role in deception detection. Findings raise questions about equitable deception detection in legal settings.