Eyewitness recollection easily distorted by the views of others

Dara Mojtahedi -- who lectures in forensic psychology -- has been carrying out innovative research into the reliability of eyewitness statements and has been disseminating his findings at conferences and during talks with police.

During an earlier phase of research he screened footage of an actual violent incident to groups of "witnesses" -- specially recruited volunteers. Some of them were allowed to confer, and it was found that many people's recollection of what they saw was readily distorted by comments from others, including dummy eyewitnesses who purposely suggested that the wrong man had started the fight.

This resulted in many inaccurate and misleading statements from people susceptible to being influenced by others.

Now Dara has developed the project, in order to discover the extent of what he describes as "co-witness familiarity on statement similarity."

He recruited 420 participants. They were placed in groups that included relations or people who had known each other for at least three months. They then watched the fight footage and held a discussion before giving individual statements privately. It was found that the post-event discussions significantly increased the level of statement similarity when the co-witnesses had a pre-existing relationship.

One reason the findings are important is that studies have shown that 86 per cent of eyewitnesses are known to each other, meaning there is enormous scope for misleading statements to be made.

As a psychologist, Dara Mojtahedi -- who is completing his PhD on eyewitness reliability -- was unsurprised by the findings of his latest experiment.

"When we encounter information from a stranger, we have no background knowledge of them to help us decide on whether they are more likely to be correct than we are. But with friends and family members, we have known them for a long time and it is a natural process that when we like someone we spend less time questioning and criticising their reliability and accuracy."

Dara has presented his research at academic events, such as the recent Forensic Psychology in Canada Conference, held in Ottawa, and at the British Psychological Society in Bristol. Also, he is supervising Master's students who are writing dissertations in the subject area.

But he is particularly determined that his findings about eyewitness reliability and especially co-witness familiarity should make an impact on police investigation and court procedures.

"A big question that police officers, lawyers and indeed jurors should be asking is, did you witness this incident with friends or did you witness it with strangers?" said Dara.

He has recently presented his work to West Yorkshire Police and his ideas were well-received. "This research is really aimed at officers and at jurors rather than an academic audience," he said.