Reducing the biasing effects of judges' nonverbal behavior with simplified jury instruction.

This research hypothesized that using simpler jury instructions would reduce jurors' reliance on judges' nonverbal behavior. Mock jurors were given either standard or simplified jury instructions, heard actual trial testimony, and then saw a judge reading jury instructions (i.e., a judge who had an expectation or belief of either guilt or innocence for a defendant). This experiment was conducted twice, once with a student population and once with an adult population. For the students, neither the judges' expectations nor the jury instructions were strongly related to the jurors' verdicts. For the adults, jurors returned more guilty verdicts overall when judges thought the defendant was guilty, and this trend was moderated by the jury instructions. The relationship between judges' expectations and jurors' verdicts was strongly positive when standard instructions were given but was weaker and in the opposite direction when simplified instructions were given.