Near the beginning of many judgments after a trial there is a section where the judge gives their view of the reliability and credibility of the witnesses. In about 98% of cases it is not necessary to read further to find out who the winner is going to be. The judge’s assessment of the witnesses is usually the key factor in the case. Penny Cooper is an expert in the effective participation of vulnerable witnesses and parties. Here she sets out the academic research on this issue.
Spotting signs that a witness is lying is a challenge for trial lawyers and fact-finders. Lawyers do not always see eye to eye (no pun intended) on the value of non-verbal ‘cues’, and neither do academics.
…most cues to deception are too faint for reliable detection, most facial expressions and other non-verbal cues are unrelated to deception, legal professionals (and others) are unable to accurately detect deception beyond chance levels, and that training people to use non-verbal cues to improve their deception detection is unviable.
While everyone knows that memory is fallible, I do not believe that the legal system has sufficiently absorbed the lessons of a century of psychological research into the nature of memory and the unreliability of eyewitness testimony.
Memory is an active process, subject to individual interpretation or construction. Each witness will have produced their witness statements many months ago, will have been asked to read or re-read their statement and review documents before giving evidence in court. There is high level commentary that reveals that this process reinforces a memory, even if the memory was false to begin with, and may cause a witness’s memory to be based not on the original experience of events but on the material which has been read and re-read. This is supported by the recent research undertaken by Elizabeth Loftus, professor of law and cognitive science at the University of California which reveals the malleability of memory by showing that witness testimony can, after the fact, be shaped and altered.
Psychological research which is valid and relevant to witness evidence is always likely to spark interest from judges and lawyers and is potentially of assistance to fact-finders. However, despite the fact that lie detection has been ‘the subject of extensive research since the 1960’s’ (Denault & Jupe, 2018) there is very little research specifically about witness deception in the courtroom. Although there is extensive research-based practice guidance on questioning vulnerable witnesses (see for example the evidence-based guide Achieving Best Evidence in Criminal Proceedings, MoJ, 2011 and https://www.theadvocatesgateway.org ), there is nothing equivalent in relation to questioning (supposedly) ‘robust’ adult witnesses in court. The English trial system draws heavily on witness evidence yet has only just begun to explore how psychological research could help the civil courts obtain and evaluate evidence from witnesses.