First published by Kaya Burgess in The Times.
Jurors who swear on the Bible are more likely to find a defendant guilty if he or she declines to do the same and takes a non-religious oath instead, a study has found.
Researchers have warned that the effect of this “discrimination against atheists” from jurors who choose a religious oath could be enough to “tip the balance” between acquittal and conviction in close trials, with the number of affected cases “potentially in the hundreds every year”.
They concluded that the swearing of religious oaths in court was “an antiquated legal ritual in need of reform”.
The religious oath starts with the words, “I swear by Almighty God” while the non-religious affirmation starts with, “I solemnly, sincerely and truly declare and affirm”. Both pledge to tell “the truth, the whole truth and nothing but the truth” and are equally binding legally.
Researchers at Royal Holloway, University of London, wanted to see whether jurors were generally biased for or against those who took a non-religious oath and whether jurors were more likely to favour defendants who took the same oath as they did.
The researchers set up a mock trial with images and audio recordings of a defendant charged with robbery and asked 1,821 people to act as jurors, listening to testimony from the arresting officer, a witness, an alleged victim and the defendant. The script, used in previous studies, was designed to produce an even split of verdicts.
The jurors were asked to choose between a religious and non-religious oath and told which option was chosen by the defendant. Twenty-eight per cent of jurors chose the religious oath and 72 per cent chose the secular affirmation.
The verdicts returned were 47.4 guilty and 52.6 per cent not guilty overall. Wider differences emerged when jurors were split by type of oath, however.
“Mock jurors who themselves swore a [religious] oath discriminated between defendants who swore [a religious oath] and those who affirmed [a non-religious declaration], finding the latter guilty at a higher rate,” concluded the study, published in the British Journal of Psychology. It found that jurors who took a religious oath saw “perceived defendants who affirmed [a non-religious oath] as guiltier”.
Ryan McKay, lead author of the study and a psychology professor at Royal Holloway, said: “There were 514 jurors in our dataset who chose to swear the oath. Of these, 60 per cent of those who tried the defendant who made a secular declaration found him guilty, whereas 49 per cent of those who tried the defendant who made a religious declaration found him guilty.”
The study found that jurors who chose the non-religious declaration showed no discernible bias based on the oath chosen by defendants.
The study suggested that some jurors “consider the [religious] oath the traditional and therefore correct declaration”. Defendants who chose the non-religious affirmation may in their eyes “appear less credible, biasing trial outcomes in any number of ways”.
The researchers warned: “The biases could potentially tip the balance in cases that could go either way.”
In 2013, the Magistrates’ Association rejected proposals to abolish religious oaths.
Kirsty Brimelow KC, head of the Criminal Bar Association, said: “I very much doubt that affirming or swearing to a religion makes a difference between conviction and acquittal. My experience is that it is the evidence that is the focus of juries. By the time juries come to deliberate, after speeches and summing up, including written directions and route to verdict, they likely will have forgotten what oath a defendant took.”