Kenneth Clarke, many Lib Dems favourite Tory, said last weekend that women should not be allowed to be veiled when giving evidence in court. This is at odds with the views of the Home Secretary, Theresa May, who has been reported in the past as saying that women should be free to wear what they want, except in exceptional circumstances.
His argument is that for a court to determine whether a witness is telling the truth, it is important to be able to see a person’s body language. A veil, therefore, prevents this from happening. The radio interview I heard him speak in said that his view on the matter was “commonsense”.
Well, it may be commonsense, but it is at odds with a significant body of psychological research into deception.
One of the most published and respected researchers in this field is Aldert Vrij. In his book, Detecting Lies and Deceit, he discusses a number of studies and experiments that have investigated the public’s ability to determine if someone they do not know is telling the truth. Where people are asked to judge if someone is telling the truth, success rates vary between 49% and 81%, averaging a little over 63%. If they are asked to determine if someone is lying, success rates vary between 27% and 70% and are often below 50%, with an average score across 34 studies of approximately 48%.
48% is less than chance – in other words, a better decision would probably have been made by simply tossing a coin.
Vrij suggests that one explanation for this is that most people base their judgements on what they believe are good cues to deception, such as gaze aversion or using a hand to hide the mouth or eyes.
However, many of these “commonsense” cues are not, in reality, good predictors of deception at all. Worse, belief in their predictive power may simply serve to mislead. It is partly due to these widely held beliefs in non-verbal cues to deception which means that motivated liars are often very good at avoiding these behaviours, and so are able to mislead people who seek to base their judgements on demeanour alone.
Instead, a better way to tell if someone is being truthful is to listen to the content of what they say and then to determine if it is backed up by other more reliable forms of evidence.
Psychological research into deception might therefore lead you to suppose that there would be a far better case for arguing that everyone who gives evidence in court, regardless of faith or cultural background, should be veiled in order to stop juries making faulty decisions based simply on a person’s demeanour.