Kerwin, J., & Shaffer, D. R. (1994). Mock jurors versus mock juries: The role of deliberations in reactions to inadmissible testimony. Personality and Social Psychology Bulletin, 20, 153-162.
The consensus among authors in the area of juridic decision making is that trial jurors often readily disregard judicial instructions to ignore inadmissible evidence. Perhaps, however, the moderating influence of a key methodological variable-the presence or absence of group deliberations-has been overlooked by those making this assertion. It was hypothesized that mock juries (who participate in deliberations) would be more likely to follow judicial instructions to ignore inadmissible testimony than mock jurors (responding individually, without deliberations). Results supported this hypothesis.
Verdicts of deliberating juries were appropriately influenced by judicial instructions regarding the admissibility of evidence, whereas the verdict preferences of individual jurors were not.