When we ‘see things with our own eyes, we may feel that our recollection of events cannot be doubted. Yet psychologists have discovered that our openness to suggestion and confusion about where and when we saw what can make us unreliable eyewitnesses.
Imagine that you have witnessed a theft, and the police have asked you to look through photographs of known criminals to see if you can identify the thief. You might not be able to spot a familiar face among them, but what if you were called in for an identity parade a week later? You might think that you would spot the thief in the line-up with no trouble – but research has shown that you’d be quite likely to pick up someone whose phone you had seen the previous week rather than the real criminal.
Source amnesia
Psychologists use the term ‘source amnesia’ to describe the uncertainty about where people are remembering something from. We are all prone to source amnesia, but some of us are more vulnerable than others. Young children can confuse the things they see on television with what they experience in real life, while older people can find it hard to remember who said what. As a result, law courts can sometimes be skeptical about the quality of evidence given by the very young or the very old.
Many legal cases rely heavily on eyewitnesses, and yet it has been estimated that unreliable eyewitness testimony leads to as many as 4500 false convictions a year in the USA alone. Source amnesia could play a part in many of them. For example, imagine what might happen if, during the police interview process or in a court of law, key facts are ‘suggested ‘ to an eyewitness, perhaps by using leading questions such as ‘Did the suspect strike the victim?’ Later, it can become genuinely difficult for a witness to keep the new ‘sug gested memories’ separate from the memory of what they actually saw.
Misleading information
The US memory researcher Elizabeth Loftus was one of the first people to explore in detail how witnesses can be influenced by information suggested to them after the event. In a pioneering series of studies in the 1970s, Loft showed a group of people a film of a staged car crash and then asked how fast they thought the cars were traveling when they hit each other. All the volunteers were asked essentially the same question, but for some, Loftus used words such as ‘contacted,’ ‘bumped,’ ‘collided,’ or ‘smashed’ instead of ‘hit. ‘ She found that the speeds put forward by the volunteers were directly influenced by the words she used -those who had been told the cars merely ‘contacted’ estimated lower speeds than those who were told the cars had ‘smashed.’ A week later, Loftus found that those who had been asked the question with the word ‘smashed’ in it were also more likely to ‘remember’ seeing broken glass lying on the road after the accident – although no glass was actually there.
Cognitive interviews
Police forces in countries around the world are responding to research findings on the reliability of eyewitness memory by introducing new interview procedures called cognitive interviews. Psychologists specially design these to help witnesses generate more accurate testimonies. Cognitive interviews are successful because they increase the number of cues derived from the context of an event that is available to a witness – for example, the sights, sounds, and smells that were present at the time, as well as the feelings of the witnesses themselves. We can remember more about an event if the context is reinstated, which is why police often take victims and witnesses back to the scene of a crime.
The Suggestibility Of Young Children
The fact that children tend to be suggestible frequently causes problems when child witnesses or possible victims of child abuse are questioned. It is one reason why, in the UK, children’s evidence is videotaped as soon as possible after the event.
Psychologist Stephen Ceci and his team demonstrated how easy it is to influence young children’s memories. They told a story to groups of children between the ages of 3 and 12 and also showed drawings of the major sections of the story. The next day, an adult suggested to half the children details that had not been in the original story. Two days later, all the children were tested on recognition memory. They were shown pictures that had been presented during the story and pictures of suggested events that were similar to those in the story. One picture showed a girl eating eggs (as in the story), and another showed the girl eating cereal (an adult suggestion). The children were asked to choose a picture to illustrate the story. Ceci found that younger children were much more likely than older ones to pick an image of a girl eating cereal.
Photofit Challenge
Even if you are generally confident about your memory, it is quite easy to demonstrate to yourself how fallible you might be as an eyewitness.
- Try to generate a full description of someone you see regularly but don’t know well- for example, the postman or a local shopkeeper. Write down details such as eye and hair color, hairstyle, build, any facial hair, whether they wear glasses, and any particular distinguishing features. You could even try to sketch them, like a police artist.
- Keep your notes handy, and the next time you see the person, check off the features you remembered correctly and those you didn’t. How accurate was your description?
