Expert Evidence

, Volume 7, Issue 1, pp 25–36

Accuracy and confidence in detecting truths andlies in elaborations and denials:Truth bias, lie bias and individual differences

  • Aldert Vrij
  • Mark Baxter


Accuracy in the ability to detect truths and lies isimportant in a legal setting. It might be used as atool in police investigations to eliminate potentialsuspects, to check the truthfulness of informants orto examine contradictory statements of witnesses andsuspects in the same case. A consistent finding in thedetection of deception literature is the truthbias: People's accuracy at detecting truths isusually higher than their accuracy at detecting lies.The present article examines whether the existence ofa truth bias depends on the type of lie. It is arguedthat a truth bias may occur when people judgeextensive statements (e.g. elaborations), but that alie bias may occur when people judge statements whichdo not provide much verbal information (e.g. denials).Fifty participants (college students) were exposed to20 video fragments of 20 people telling elaborations(10) or denials (10). Half of the elaborations anddenials were truthful, the other half were deceptive.After each fragment, the participants were asked toindicate whether the person was lying or telling thetruth and how confident they were in their decisionmaking. As predicted, with regard to elaborations atruth bias was found and with regard to denials a liebias was found. In other words, people have difficultyin accurately judging deceptive elaborations andtruthful denials. The study further revealedindividual differences in participants' confidence atdetecting deceit. The more socially anxious/shy theparticipants reported themselves to be, the lessconfident they were in their ability to detect deceit.Also, the more extraverted they themselves reported tobe, the more confident they were in their ability todetect deceit. The importance of confidence onimproving people's ability to detect deceit will bediscussed.

detecting deception elaborations falsifications individual differences lie bias police truth bias 


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  1. Bell, B.E. and Loftus, E.F. (1988) “Degree of Detail of Eyewitness Testimony and Mock Juror Judgments”, Journal of Applied Social Psychology 18: 1171-1192.Google Scholar
  2. Briggs, S.R., Cheek, J.M. and Buss, A.H. (1980) “An Analysis of the Self-Monitoring Scale”, Journal of Personality and Social Psychology 38: 679-686.Google Scholar
  3. Bull, R. (1989) “Can Training Enhance the Detection of Deception?”, in Yuille, J.C. (ed.), Credibility Assessment. Dordrecht, the Netherlands: Kluwer, pp. 83-97.Google Scholar
  4. Cheek, J.M. and Buss, A.H. (1981) “Shyness and Sociability”, Journal of Personality and Social Psychology 41: 330-339.Google Scholar
  5. DePaulo, B.M., Charlton, K., Cooper, H., Lindsay, J. L. and Muhlenbruck, L. (1997) “The Accuracy-Confidence Correlation in the Detection of Deception”, Personality and Social Psychology Review 1: 346-357.Google Scholar
  6. DePaulo, B.M. and Kirkendol, S.E. (1989) “The Motivational Impairment Effect in the Communication of Deception”, in Yuille, J.C. (ed.), Credibility Assessment. Dordrecht, the Netherlands: Kluwer, pp. 51-70.Google Scholar
  7. Ekman, P. (1992) Telling Lies: Clues to Deceit in the Marketplace, Politics and Marriage. New York, NJ: W. W. Norton.Google Scholar
  8. Ekman, P. and Friesen, W.V. (1974) “Detecting Deception from the Body or Face”, Journal of Personality and Social Psychology 29: 288-298.Google Scholar
  9. Fenigstein, A., Scheier, M.F. and Buss, A.H. (1975) “Public and Private Self-Consciousness: Assessment and Theory”, Journal of Consulting and Clinical Psychology 43: 522-527.Google Scholar
  10. Kashy, D.A. and DePaulo, B.M. (1996) “Who Lies?”, Journal of Personality and Social Psychology 70: 1037-1051.Google Scholar
  11. O'Sullivan, M., Ekman, P. and Friesen, W.V. (1988) “The Effect of Comparisons on Eetecting Deceit”, Journal of Nonverbal Behavior 12: 203-216.Google Scholar
  12. Vrij, A. (2000) Detecting Lies and Deceit: The Psychology of Lying and Implications for Profession Practice. Chichester: Wiley and Sons.Google Scholar
  13. Vrij, A., Harden, F., Terry, J., Edward, K. and Bull, R. (1999) The Influence of Personal Characteristics, Stakes and Lie Complexity on the Accuracy and Confidence to Detect Deceit. Manuscript submitted for publication.Google Scholar
  14. Vrij, A. and Semin, G.R. (1996) “Lie Experts' Beliefs about Nonverbal Indicators of Deception”, Journal of Nonverbal Behavior 20: 65-80.Google Scholar
  15. Wells, G.L. and Leippe, M.R. (1981) “How Do Triers of Fact Infer Accuracy of Eyewitness Identification? Using Memory of Peripheral Details Can be Misleading”, Journal of Applied Psychology 66: 682-687.Google Scholar
  16. Zuckerman, M., DePaulo, B.M. and Rosenthal, R. (1981) “Verbal and Nonverbal Communication of Deception”, in Berkowitz, L. (ed.), Advances in Experimental Social Psychology, Volume 14. New York, NJ: Academic Press, pp. 1-57.Google Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Aldert Vrij
    • 1
  • Mark Baxter
    • 1
  1. 1.Psychology DepartmentUniversity of PortsmouthPortsmouthUnited Kingdom

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