Effects of inadmissible Evidence on the Decisions of Simulated Jurors: A Moral Dilemma


Requests for reprints should be sent to Dr. Stanley Sue, Department of Psychology, University of Washington, Seattle, Washington 98195.


In a 2 × 3 design, simulated jurors received either weak or strong evidence against a defendant in a murder case. Within each evidence condition, subjects were given either additional evidence ruled admissible, additional evidence ruled inadmissible, or no additional evidence. Results indicated that (a) jurors were biased by inadmissible evidcnce in the weak-evidence but not in the strong-evidence condition, (b) strong evidence resulted in more guilty verdicts than did weak evidence, (c) confidence in verdict was influenced by strength of evidence, and (d) confidence of guilt was positively correlated with severity of punishment. Implications of the results are discussed within the context of the judicial process.