Group-Based Biases and Validity in Eyewitness Credibility Judgments: Examining Effects of Witness Ethnicity and Presentation Modality1


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    This research was supported by Grant #F0398/99 from the Swedish Research Council.

Correspondence concerning this article should be addressed to Torun Lindholm, Malardalen University, Box 883, 721 23 Vasteras, Sweden. E-mail:


To study how witness ethnicity and testimony presentation mode affected judgments of eyewitness credibility, testimonies from 6 immigrant and 6 Swedish accuracy-matched witnesses to a crime were presented to Swedish fact finders (N= 120) in videotape or as a transcript. Results showed that witnesses were perceived as more credible in the visual as compared to the written medium. Moreover, witness ethnicity affected judgments differentially depending on presentation mode for fact finders high in prejudice toward immigrants. Results also revealed that fact finders’ judgments corresponded with the self-reported confidence of Swedish, but not immigrant witnesses and that in the transcript condition, judgmental validity was lower in estimates of Swedes’ as compared to immigrants’ accuracy. The findings indicate that presentation mode can function as a moderator of group-based effects in social judgments, and that both psychological theory and judicial systems need to consider thoroughly how different stimulus presentations compare in terms of the impact on perceivers.