Study finds juror bias against those who don’t swear to God

new study of British citizens has found for the first time that defendants who don’t ‘swear by Almighty God’ in court are more likely to be found guilty by jurors who do. The research is published today (Tuesday) in The British Journal of Psychology and was conducted by Professor Ryan McKay of Royal Holloway, University of London with Dr Will Gervais from Brunel University London and Professor Colin Davis from the University of Bristol. Humanists UK has said that the practice of defendants swearing an oath or affirming in front of the judge and jurors needs to end.

Currently, defendants in the UK, the US, Australia, and elsewhere have to either swear an oath with a religious text, or make a secular affirmation. A minority of religious people object to making a religious oath for religious reasons. But the research has established that most of those who make a secular affirmation do so because they are non-religious. As a result the oath and affirmation process is frequently presumed to reveal the defendants’ beliefs.

The new research

What the new research found is that in general terms people associate the religious oath with credible testimony; and that certain jurors are biased against defendants who choose instead to affirm. More specifically, participants in the main study were shown a mock trial in which a defendant either swore an oath or affirmed. Jurors who swore a religious oath were more likely to find the defendant guilty if the defendant affirmed.

(There wasn’t much difference in the results between jurors who swore a religious oath’s views on defendants who swore, when compared to jurors who affirmed’s views on defendants who swore. Nor was there much of a difference when it came to jurors who affirmed’s views on defendants who affirmed. It was just jurors who swore an oath’s views on defendants who affirmed that were significantly different.)

The authors speculate that the number of additional convictions of the non-religious, compared to religious, that may result from this bias could number ‘potentially in the hundreds every year’.

Two possible solutions

Humanists UK has called for an end to the practice of defendants and jurors swearing an oath or affirming in front of the judge and (other) jurors. It sees two possible ways forward.

One solution is to abolish the oath entirely and just allow secular affirmation: ‘I solemnly, sincerely and truly declare and affirm that the evidence I shall give shall be the truth, the whole truth and nothing but the truth.’

Another is, in addition to requiring everyone to make a secular affirmation, to allow religious people to swear an oath in private in front of court officials who have no connection to the judge or (other) jurors. Some people argue that swearing a religious oath makes religious people more honest. Humanists UK knows of no evidence for that, but this solution should satisfy those who believe this to be true.

Professor Ryan McKay, from the Department of Psychology at Royal Holloway, University of London, who led on the study, commented:

‘If taking the oath is seen as a sign of credibility, this could lead to discrimination against defendants who are not willing to swear by God. An earlier proposal to abolish the oath in England and Wales was defeated when opponents argued that the oath strengthens the value of witnesses’ evidence. This is ironic, as it seems to acknowledge that swearing an oath may give an advantage in court.’

Humanists UK Director of Public Affairs and Policy Richy Thompson commented:

‘It is alarming to hear that people may be being wrongly imprisoned because they are forced to take an action that leads prejudiced religious jurors to perceive them as non-religious. There is no reason why jurors should know a defendant’s religion or belief. Given that prejudice based on religion or belief is still too common in the UK today, it would be best to reform the oath and affirmation system to one that doesn’t reveal this information to jurors.’