Abstract
Judgments about others are often based on information that varies in terms of its diagnosticity or usefulness in predicting a certain outcome. Previous studies have demonstrated a “dilution effect” in which the addition of nondiagnostic or irrelevant information yields less extreme judgments than those based solely on diagnostic information. Two studies investigated the dilution effect in a juror decision making context in which no midpoint of a scale was provided by researchers. Study 1 examined the inclusion of positive, negative, or neutral character information in a criminal case and found that this nondiagnostic information affected attitude toward the defendant but did not “dilute” guilt judgments. The cases in Study 1 contained a larger amount of diagnostic information than studies that demonstrated the dilution effect. Thus, the amount of diagnostic evidence provided was varied in Study 2, and the results showed “diluted” judgments only when a small amount of diagnostic information was presented. Limitations to the dilution effect were discussed.
Similar content being viewed by others
References
Alicke, M.D. & Yurak, T.J. (1995). Perpetrator personality and judgments of acquaintance rape. Journal of Applied Social Psychology, 25, 1900–1921.
Cooper, W.H. (1981) Ubiquitous halo. Psychological Bulletin, 90, 218–244.
De Dreu, C.K.W., Yzerbyt, V.Y., & Leyens, J. (1995) Dilution of stereotype-based cooperation in mixed motive independence. Journal of Experimental Social Psychology, 31, 575–593.
Fiske, S.T., & Taylor, S.E. (1991). Social cognition (2nd edition). New York: McGraw-Hill.
Hastie, R. (Ed.). (1993). Inside the juror: The psychology of juror decision making. Cambridge: Cambridge University Press.
Kahneman, D. and Tversky, A. (1973). On the psychology of prediction. Psychological Review, 80, 237–251.
Kahneman, D., Slovic, P., & Tversky, A. (Eds.). (1982). Judgment under uncertainty: Heuristics and biases. Cambridge: Cambridge University Press.
Kaplan, M. F. & Miller, L.E. (1978). Reducing the effects of juror bias. Journal of Personality and Social Psychology, 36, 1443–1455.
Kerr, N.L. (1982). Trial participants behaviors and jury verdicts: An exploratory field study. In Konecni, V.J. & Ebbesen, E. (Eds.), The criminal justice system: A social-psychological analysis. San Francisco: Freeman.
Macrae, C.N., Shepherd, J.W., & Milne, A.B. (1992). The effects of source credibility on the dilution of stereotype-based judgments. Personality and Social Psychology Bulletin, 18, 765–775.
Nisbett, R. E., Zukier, H., & Lemley, R.E. (1981). The dilution effect: Nondiagnostic information weakens the implication of diagnostic information. Cognitive Psychology, 13, 248–277.
Reisberg, D. (1997). Cognition: Exploring the science of the mind. New York: W.W. Norton & Company.
Tetlock, P. E., & Boettger, R. (1989). Accountability: A social magnifier of the dilution effect. Journal of Personality and Social Psychology, 57, 388–398.
Troutman, C. M., & Shanteau, J. (1977). Inferences based on nondiagnostic information. Organizational Behavior and Human Performance, 19, 43–55.
Tversky, A. (1977). Features of similarity. Psychological Review, 84, 327–352.
Wrightsman, L. S., Nietzel, M. T., & Fortune, W. H. (1994). Psychology and the legal system (3rd ed.). Belmont, CA: Wadsworth.
Zukier H. (1982). The dilution effect: The role of correlation and the dispersion of predictor variables in the use of nondiagnostic information. Journal of Personality and Social Psychology, 43, 1163–1174.
Zukier, H., & Jennings, D.L. (1983-1984). Nondiagnosticity and typicality effects in prediction. Social Cognition, 2, 187–198.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Smith, H.D., Stasson, M.F. & Hawkes, W.G. Dilution in legal decision making: Effect of non-diagnostic information in relation to amount of diagnostic evidence. Curr Psychol 17, 333–345 (1998). https://doi.org/10.1007/s12144-998-1015-6
Issue Date:
DOI: https://doi.org/10.1007/s12144-998-1015-6