10 January 2014
Bias has ‘significant’ effect on verdicts, jury research says
"Jurors should be tested before trials to reduce the effect of prejudices on their understanding of the burden of proof, according to the authors of a study suggesting bias has a ‘significant’ impact on verdicts.
A study, published in the British Psychological Society’s Legal and Criminological Psychology journal, found that pre-trial bias and jurors' understanding of the concept of beyond reasonable doubt have a ‘significant’ impact on the verdict they are likely to deliver in court.
Researchers from Anglia Ruskin University, University of Cambridge and University of Manchester sampled a group of 118 people aged between 19-63 employed by a pharmaceutical company in Cambridge.
Participants were asked to imagine they were serving on a jury in a ficticious burglary trial. They were given details of the charge, the prosecution and defence cases and the judge's instructions on the presumption of innocence.
Looking at the criminal standard of proof to convict - beyond reasonable doubt - the study found that the average threshold required to find someone guilty was a probability of 95%.
It also found that pre-trial attitudes combined with interpretations of beyond reasonable doubt accounted for 37% of the variability in the verdicts, so are an important predictor of how a juror will decide, regardless of the evidence."