Biases in eyewitness identifications in police line-ups have been observed empirically. Now scientists would be finding out more about these biases to determine if people avoid pointing the finger at someone they like in a police line-up.
Eyewitness misidentification is the biggest cause of wrongful convictions the world over. In the US alone, more than 75 percent of convictions have been overturned through DNA testing. Till now, however, no one has studied this aspect of human behaviour.
Psychologists Dr Hartmut Blank and Dr Jim Sauer of the University of Portsmouth, UK will delve into this by studying eyewitness memory and "liking bias". Pilot research by the two psychologists indicates that people are more likely to identify line-up members they dislike as the perpetrator of a crime and less likely to identify someone they like. Such decisions are automatic and spontaneous rather than thought out.
“It’s natural that we don’t enjoy creating trouble for someone we like by identifying them as a perpetrator. Our contribution is to apply this insight to eyewitness identification because nobody has studied this before," says Dr Blank, a specialist in memory and the effect of social influences on how and what we remember.
The researchers will conduct four experiments trying to identify the underlying causes and boundaries of liking bias in the hope that they can then find ways of limiting or eliminating the effect of such bias in real-world identification procedures. The study is being funded by a £100,000 Economic and Social Research Council grant.
“The feeling of liking can definitely influence judgement. The liking bias is a subtle effect though – otherwise the justice system would have long been aware of it,” Dr Blank says.
Dr Sauer, on the other hand, is interested in the effect of liking bias because of the growing number of documented cases in which mistaken identifications contributed to the convictions of people who were later proved through DNA testing to be innocent.
According to the Innocence Project, US, eyewitness misidentifications contributed to over 75 per cent of the more than 220 wrongful convictions in the US overturned by post-conviction DNA evidence.
- Inaccurate eyewitness identifications can confound investigations from the earliest stages. Critical time is lost while police are distracted from the real perpetrator, focusing instead on building the case against an innocent person.
- Despite solid and growing proof of the inaccuracy of traditional eyewitness ID procedures – and the availability of simple measures to reform them - traditional eyewitness identifications remain among the most commonly used and compelling evidence brought against criminal defendants.
Dr Sauer explains, “The legal system finds eyewitness identification evidence compelling but it has contributed to many wrongful convictions over the years. Eyewitness error represents a significant cost to society and criminal justice system. The first cost is an innocent person is jailed; the second cost is once an individual has been identified, police investigations may narrow, so the perpetrator remains at large."
He continues, “Most people think their memories are reliable but no-one is exempt from vulnerability to bias. Some people are more resistant than others; generally, those with better memories of an event are more resistant to biases, and those with poorer memories of an event are more vulnerable.
“In a police line-up, the witness goes in thinking they have a job to do. They assume the police have caught someone and that person is standing in the line-up. They also assume the police have other information to back up their arrest or suspicions. They think their job is to pick the suspect. If the eyewitness has no clear memory of the perpetrator, they look for cues available in the identification situation – perhaps subconsciously they just don’t like the look of someone in the line-up, so they point to them.”
But, would this kind of eyewitness (mis)identification be specific to line-ups where there is no face-to-face interaction with the suspect? Dr Blank answers, "The immediate answer is that we don't know, simply because we are only starting to investigate liking bias. The psychological theory on which this research is based would not necessarily expect any difference, i.e. we don't think this phenomenon would be specific to line-ups. But, again, there is no available evidence that would conclusively show this at the moment."
And can the same logic can be extended to other cases? For instance, eyewitnesses narrating an event to a journalist. Dr Blank, a Senior Lecturer at the University, says, "Pretty much the same explanation would apply. General psychological theory and knowledge would predict that liking bias should be expected in such a situation, but this not yet been specifically demonstrated empirically."
