The effect of language proficiency on second-language lie detection.

Abstract

I examined whether observers’ own language proficiencies would affect their lie detection judgments. In a previous study, native- and second-language English speakers were videotaped as they either lied or told the truth about having cheated on a test (Da Silva & Leach, 2013). A total of 284 undergraduate students viewed the videos and were asked to indicate whether they believed that the individuals were being truthful or deceptive. Observers performed better when judging native-language speakers than second-language speakers. Furthermore, observers’ own language proficiencies had an effect on bias: as the proficiency of observers decreased, they were more likely to judge speakers as truth-tellers. However, there was no effect of language proficiency on discrimination. These findings may inform law enforcement hiring practices. In addition, they suggest that the use of interpreters in legal processes may be essential. Implications of these findings will be further discussed.