Accuracy and Confidence on the Interpersonal Perception Task: A Japanese-American Comparison

Abstract

This study compared the accuracy and confidence of Japanese and American participants on the Interpersonal Perception Task (IPT-15). The IPT contains 15 brief, real-life scenes on videotape for which there are objectively correct answers about relationships and deception. A total of 344 participants were run in a 2 (Japanese vs. American participants) × 2 (Audiovisual vs. Visual-Only presentation) × 2 (Sex of participant) design. Support was found for the hypothesized greater accuracy of Americans over Japanese, but a Culture × Presentation Modality interaction qualified the main effect of culture. Specifically, Japanese and American participants had virtually identical scores on the IPT-15 in the Visual-Only condition, but Americans' scores increased while Japanese scores decreased in the Audiovisual condition. Analyses of the confidence measures indicated that American participants were much more confident than the Japanese participants, but this difference was larger in the Audiovisual condition than in the Visual-Only condition. In addition, the prediction that women would be more accurate on the IPT, but still report lower confidence than men, was also supported. Finally, Japanese participants with moderate proficiency in spoken English were more accurate on the IPT than those with low English proficiency. The likely processes underlying these differences and the possible directions for future research are discussed.