Dateline: December, 2006, Issue 3
Jurors are often instructed by a judge to disregard inadmissible testimony after objection by an attorney. Wilson (2004) recently tested, in two studies, whether an attorney's objection increases the likelihood that the objected-to testimony influences jurors' verdicts.
The first study found that jurors overweight testimony that follows an objection, and that the content of an interruption is important to juror verdicts. When an interruption is devoid of any trial-relevant information, jurors return fewer guilty verdicts, whereas when an interruption is filled with information about the objected-to testimony, jurors are more likely to vote guilty. Jurors were unable completely to disregard inadmissible testimony when instructed to do so.
The second study found that when a judge instructs jurors to disregard testimony at the end of the trial, jurors are more likely to do so than when this instruction immediately follows the objection/testimony.
Both studies suggest that an attorney's objection increases the likelihood that the objected-to testimony will be used by jurors. The second study suggests a judicial instruction to disregard inadmissible testimony at the end of the trial is more effective than an instruction given at the time of the objection.
Source Wilson, M. J. W. (2004). Objecting to objections: The paradoxical consequences of courtroom interruptions. Dissertation Abstracts International: Section B: The Sciences and Engineering, 65(1-B), pp. 483.