The effect of target language proficiency on deception detection among undergraduate students

I examined the impact of targets??? language proficiency on observers??? lie detection accuracy, discrimination, bias, and confidence. Observers (N = 132) were randomly assigned to make deception judgments about targets (N = 56) from four proficiency groups (i.e., native, advanced, intermediate, and beginner English speakers). Overall, observers??? accuracy differed based on targets??? level of proficiency. Specifically, accuracy and discrimination were poorest when observers judged beginner English speakers compared to targets from any other proficiency group. Moreover, observers exhibited a truth bias only when they judged native English speakers. They were also more confident when detecting targets who were lie-tellers than truth-tellers. Implications and directions for future research were discussed in light of these results