Demographic and personality factors predict only 5 to 15 percent of verdict variation

Evidence

Attorneys may hire jury consultants to assist in jury selection, or they may try out arguments in front of “mock juries” before trial. They may employ “shadow juries,” people similar to those serving on the jury, who are hired to provide daily feedback on how the arguments presented in court might have been received by the jury. Whether these approaches can predict juror behavior is hotly disputed. One overview of pertinent studies concluded that when different people were presented with the same evidence, and the variations in their verdicts were examined, only 5 to 15 percent of the variations were connected to demographic and personality factors. — G. Alan Tarr, Judicial Process and Judicial…, 843

Categorization

• QUESTION: This 5-15 percent finding strongly undermines the entire scientific jury selection enterprise — worth chasing the original studies to see how verdict variation was measured and whether the figure is robust.
• XREF: Connects to the course theme that legal actors’ discretion (here jury selection) rests on far weaker empirical bases than doctrine assumes — parallels other readings on discretionary judgments in the legal system. — connects to: Demographics weakly predict how individual jurors actually vote on the same evidence — G. Alan Tarr, Judicial Process and Judicial…, 843; Individual juror bias studies may not predict deliberating jury verdicts — Joseph Avery, Jim Sidanius, Joel Cooper, Gregory Davis, Amanda N., Bias in the Law: A Definitive Look at…, 913

Broader Connections

• Demographics weakly predict how individual jurors actually vote on the same evidence #corroborates (0.90) — G. Alan Tarr, Judicial Process and Judicial…, 843
• Individual juror bias studies may not predict deliberating jury verdicts #qualifies (0.85) — Joseph Avery, Jim Sidanius, Joel Cooper, Gregory Davis, Amanda N., Bias in the Law, 913