Vol. 15 (2026)

Research Articles

Lexical Diversity Predicts Juror Perceptions of Written Eyewitness Testimony

Published 04.05.2026

  • Kelly Kendro

Kelly Kendro
Northern Arizona University

Abstract

While many studies investigate how eyewitness identities such as gender, race, and dialect might result in differing evaluations of the eyewitness’s credibility, lexical dimensions of these statements are often overlooked. Properties of language production such as lexical diversity can reveal information about a person’s language status or other identities, possibly serving as proxies for those attributes when explicit information is unavailable. Previous research has found that higher number of total (volume) and unique (abundance) words, lower type-token ratio (variety-repetition), and higher proportions of “vivid” descriptors are linked to veracity (e.g., Colwell et al., 2007; Morgan et al., 2013, 2015). However, it is unclear how more complex dimensions of lexical diversity might be related to perceived credibility.

In this study, mock jurors (n = 64) evaluated written eyewitness statements for perceived accuracy, credibility, deceptiveness, eloquence, and prestige. The statements, evaluated across six dimensions of lexical diversity (volume, abundance, variety-repetition, evenness, disparity, and dispersion), were written by L1 and L2 English speakers. Quantitative analyses indicated that volume, abundance, variety-repetition, evenness, and disparity predicted perceived integrity (accuracy, credibility, and deceptiveness), while abundance, variety-repetition, evenness, and disparity predicted perceived status (eloquence and prestige). When controlling for lexical diversity, L1 statements were nevertheless rated more positively than L2 statements. These results highlight how juror perceptions may be biased even absent explicit demographic information. Furthermore, they highlight the lexical aspects of a text on which jurors may rely when evaluating the integrity of a witness, with implications for the study of human error in veracity judgments.

 

Cite as: Kendro, JLL 15 (2026), 86–110, DOI: 10.14762/jll.2026.86

Keywords

eyewitness testimony, credibility, lexical diversity, linguistic bias

PDF

References

  1. Akbary, Mary & Jarvis, Scott (2023). Lexical diversity as a predictor of genre in TV shows. Digital Scholarship in the Humanities, 38(3), 921–936. DOI: 10.1093/llc/fqad004.
  2. Bell, Brad E. & Loftus, Elizabeth F. (1985). Vivid persuasion in the courtroom. Journal of Personality Assessment, 49(6), 659–664. DOI: 10.1207/s15327752jpa4906_16.
  3. Bell, Brad E. & Loftus, Elizabeth F. (1988). Degree of detail of eyewitness testimony and mock juror judgments. Journal of Applied Social Psychology, 18(14), 1171–1192. DOI: 10.1111/j.1559-1816.1988.tb01200.x.
  4. Bond, Charles F.; Kahler, Karen Nelson & Paolicelli, Lucia M. (1985). The miscommunication of deception: An adaptive perspective. Journal of Experimental Social Psychology, 21(4), 331–345. DOI: 10.1016/0022-1031(85)90034-4.
  5. Brönnimann, Rebecca; Herlihy, Jane; Müller, Julia & Ehlert, Ulrike (2013). Do testimonies of traumatic events dif- fer depending on the interviewer? The European Journal of Psychology Applied to Legal Context, 5(1), 97–121.
  6. Buckhout, Robert (1974). Eyewitness testimony. Scientific American, 231(6), 23–31.
  7. Builes, Juan Camilo Carvajal; Barreto, Idaly & Gutiérrez De Piñeres, Carolina (2024). Deception detection based on the linguistic style of honest and dishonest stories. The Journal of Forensic Practice, 26(1), 46–59. DOI: 10.1108/JFP-07-2023-0035.
  8. Chen, Meishan (2021). Is courtroom discourse an ‘oral’ or ‘literate’ register? The importance of sub-register. Discourse Studies, 23(3), 1–25. DOI: 10.1177/1461445620982097.
  9. Colwell, Kevin; Hiscock-Anisman, Cheryl; Memon, Amina; Rachel, Alexis & Colwell, Lori (2007). Vividness and spontaneity of statement detail characteristics as predictors 0f witness credibility. American Journal of Forensic Psychology, 25(1), 5–30.
  10. Covington, Michael A. & McFall, Joe D. (2010). Cutting the gordian knot: The moving-average type–token ratio (MATTR). Journal of Quantitative Linguistics, 17(2), 94–100. DOI: 10.1080/09296171003643098.
  11. Drobnjak, Marko (2024). Vloga Percepcije Govora Pri Oceni Verodostojnosti Pričanja. [The Role of Speech Percep- tion in Assessing the Credibility of Testimony] [Thesis, Univerza v Ljubljani]. Available at repozitorij.uni-lj.si/IzpisGradiva.php?id=159142 (accessed 12 April 2026).
  12. Durán, Pilar; Malvern, David; Richards, Brian & Chipere, Ngoni (2004). Developmental trends in lexical diversity. Applied Linguistics, 25(2), 220–242. DOI: 10.1093/applin/25.2.220.
  13. Ehrlich, Susan (2011). Courtroom Discourse. In Wodak, Johnstone & Kerswill (Eds.), The SAGE Handbook of Sociolinguistics (pp. 361–372). SAGE Publications Ltd. DOI: 10.4135/9781446200957.
  14. Frumkin, Lara A. (2007). Influences of accent and ethnic background on perceptions of eyewitness testimony. Psychology, Crime & Law, 13(3), 317–331. DOI: 10.1080/10683160600822246.
  15. Frumkin, Lara A. & Stone, Anna (2020). Not all eyewitnesses are equal: Accent status, race and age interact to influence evaluations of testimony. Journal of Ethnicity in Criminal Justice, 18(2), 123–145. DOI: 10.1080/15377938.2020.1727806.
  16. Frumkin, Lara A. & Thompson, Amanda (2020). The impact of different British accents on perceptions of eyewitness statements. Journal of Language and Discrimination, 4(1).
  17. Gharibi, Khadijeh & Boers, Frank (2019). Influential factors in lexical richness of young heritage speakers’ family language: Iranians in New Zealand. International Journal of Bilingualism, 23(2), 381–399. DOI: 10.1177/1367006917728395.
  18. Jarvis, Scott (2013a). Capturing the Diversity in Lexical Diversity. Language Learning, 63(s1), 87–106. DOI: 10.1111/j.1467-9922.2012.00739.x.
  19. Jarvis, Scott (2013b). Defining and measuring lexical diversity. In Jarvis & Daller (Eds.), Vocabulary Knowledge: Human Ratings and Automated Measures (pp. 13–41). John Benjamins Publishing Company. Jarvis, Scott (2017). Grounding lexical diversity in human judgments. Language Testing, 34(4), 537–553. DOI: 10.1177/0265532217710632.
  20. Jones, Taylor; Kalbfeld, Jessica Rose; Hancock, Ryan & Clark, Robin (2019). Testifying while black: An experimental study of court reporter accuracy in transcription of African American English. Language, 95(2), e216–e252.
  21. Kaiser, Henry F. (1974). An index of factorial simplicity. Psychometrika, 39(1), 31–36. DOI: 10.1007/BF02291575.
  22. Kassin, Saul M.; Ellsworth, Phoebe C. & Smith, Vicki L. (1989). The “general acceptance” of psychological research on eyewitness testimony: A survey of the experts. American Psychologist, 44(8), 1089–1098. DOI: 10.1037/0003-066X.44.8.1089.
  23. Kirshenbaum, Jacqueline M. & Miller, Monica K. (2021). Judges’ experiences with mitigating jurors’ implicit biases. Psychiatry, Psychology and Law, 28(5), 683–693. DOI: 10.1080/13218719.2020.1837029.
  24. Kyle, Kristopher; Crossley, Scott A. & Jarvis, Scott (2021). Assessing the validity of lexical diversity indices using direct judgements. Language Assessment Quarterly, 18(2), 154–170. DOI: 10.1080/15434303.2020.1844205.
  25. Leung, Esther S. (2008). Interpreting for the minority, interpreting for the power. In Gibbons & Turell (Eds.), Dimensions of Forensic Linguistics (pp. 197–211). John Benjamins.
  26. Lev-Ari, Shiri & Keysar, Boaz (2010). Why don’t we believe non-native speakers? The influence of accent on credibility. Journal of Experimental Social Psychology, 46(6), 1093–1096. DOI: 10.1016/j.jesp.2010.05.025.
  27. Loftus, Elizabeth F. (1996). Eyewitness Testimony. Harvard: University Press.
  28. Loftus, Elizabeth F. (2019). Eyewitness testimony. Applied Cognitive Psychology, 33(4), 498–503. DOI: 10.1002/acp.3542. DOI: 10.14762/jll.2026.86 108
  29. McCarthy, Philip M. & Jarvis, Scott (2010). MTLD, vocd-D, and HD-D: A validation study of sophisticated approaches to lexical diversity assessment. Behavior Research Methods, 42(2), 381–392. DOI: 10.3758/BRM.42.2.381.
  30. Morgan, Charles A. III; Rabinowitz, Yarin; Hilts, Deborah; Weller, Craig E. & Coric, Vladmir (2013). Efficacy of modified cognitive interviewing, compared to human judgments in detecting deception related to bio-threat activities. Journal of Strategic Security, 6(3), 100–119.
  31. Morgan, Charles A. III; Rabinowitz, Yarin; Palin, Beau & Kennedy, Kirk. (2015). Who should you trust? Discriminating genuine from deceptive eyewitness accounts. The Open Criminology Journal, 8, 49–59.
  32. O’Neill Shermer, Lauren; Rose, Karen C. & Hoffman, Ashley (2011). Perceptions and credibility: Understanding the nuances of eyewitness testimony. Journal of Contemporary Criminal Justice, 27(2), 183–203. DOI: 10.1177/1043986211405886.
  33. Pavlenko, Aneta; Hepford, Elizabeth & Jarvis, Scott (2019). An illusion of understanding: How native and non-native speakers of English understand (and misunderstand) their Miranda rights. International Journal of Speech Language and The Law, 26(2), 181–207. DOI: 10.1558/ijsll.39163.
  34. Peace, Kristine A.; Brower, Krista L. & Rocchio, Alexandra (2015). Is truth stranger than fiction? Bizarre details and credibility assessment. Journal of Police and Criminal Psychology, 30(1), 38–49. DOI: 10.1007/s11896-014-9140-7.
  35. Peer, Eyal; Rothschild, David; Gordon, Andrew; Evernden, Zak & Damer, Ekaterina (2022). Data quality of platforms and panels for online behavioral research. Behavior Research Methods, 54(4), 1643–1662. DOI: 10.3758/s13428-021-01694-3.
  36. Powell, Richard (2008). Bilingual courtrooms: In the interests of justice? In Gibbons & Turell (Eds.). Dimensions of Forensic Linguistics (pp. 131–159). John Benjamins. Available at jbe-platform.com/content/books/9789027291158-aals.5.10pow (accessed 12 April 2026).
  37. R Core Team (2025). R: A Language and Environment for Statistical Computing [Computer Software]. R Foundation for Statistical Computing. Available at R-project.org/ (accessed 12 April 2026).
  38. Read, John & Nation, Paul (2006). An investigation of the lexical dimension of the IELTS Speaking Test. In McGovern & Walsh (Eds.), IELTS Research Reports, 6. IELTS Australia and British Council.
  39. Reyes, Robert M.; Thompson, William C. & Bower, Gordon H. (1980). Judgmental biases resulting from differing availabilities of arguments. Journal of Personality and Social Psychology, 39(1), 2–12. DOI: 10.1037/0022-3514.39.1.2.
  40. Rickford, John R. & King, Shareese (2016). Language and linguistics on trial: Hearing Rachel Jeantel (and other vernacular speakers) in the courtroom and beyond. Language, 92(4), 948–988.
  41. Ruva, Christine L.; Sykes, Elizabeth C.; Smith, Kendall D.; Deaton, Lillian R.; Erdem, Sumeyye & Jones, Angela M. (2024). Battling bias: Can two implicit bias remedies reduce juror racial bias? Psychology, Crime & Law, 30(7), 730–757. DOI: 10.1080/1068316X.2022.2115494.
  42. Schmid, H. (1997). Probabilistic part-of-speech tagging using decision trees. In Jones & Somers (Eds.), New Methods in Language Processing. Routledge.
  43. Schmid, Monika S. & Jarvis, Scott (2014). Lexical access and lexical diversity in first language attrition. Bilingualism: Language and Cognition, 17(4), 729–748. DOI: 10.1017/S1366728913000771.
  44. Tabachnick, Barbara G. & Fidell, Linda S. (2007). Using Multivariate Statistics, 5th Ed. Allyn & Bacon/Pearson Education. Treffers-Daller, Jeanine (2013). Measuring lexical diversity among L2 learners of French: An exploration of the validity of D, MTLD and HD-D as measures of language ability. In Scott Jarvis & Michael Daller (Eds.), Studies in Bilingualism, 47, 79–104. John Benjamins Publishing Company. DOI: 10.1075/sibil.47.05ch3.
  45. Vidal, Karina & Jarvis, Scott (2020). Effects of English-medium instruction on Spanish students’ proficiency and lexical diversity in English. Language Teaching Research, 24(5), 568–587. DOI: 10.1177/1362168818817945. DOI: 10.14762/jll.2026.86 109
  46. Wells, Gary L. & Turtle, John W. (1987). Eyewitness testimony research: Current knowledge and emergent controversies. Canadian Journal of Behavioural Science / Revue Canadienne Des Sciences Du Comportement, 19(4), 363–388. DOI: 10.1037/h0080000.
  47. Yoon, Hyung-Jo (2017). Linguistic complexity in L2 writing revisited: Issues of topic, proficiency, and construct multidimensionality. System, 66, 130–141. DOI: 10.1016/j.system.2017.03.007.
  48. Zenker, Fred & Kyle, Kristopher (2021). Investigating minimum text lengths for lexical diversity indices. Assessing Writing, 47, 100505. DOI: 10.1016/j.asw.2020.100505.