Memory conformity between eyewitnesses

Fiona is a Professor of Psychology and Director of the Forensic Psychology Unit at Goldsmiths. She also chairs the Scientific Committee of the International Investigative Interviewing Research Group (iIIRG), and acts as Associate Editor for the academic journal ‘Memory’. Fiona has an international reputation for her research on the suggestibility of memory and investigative interviewing, that has had an international impact on police operational procedure and policy. She is currently working with the United Nations advising on the development of a Universal Protocol on investigative interviewing. Her work has been recognised by awards for Academic Excellence, Mid-Career Excellence, and Public Engagement.

People talk to one another about their memories all the time, either for the fun of reminiscing about a past event, or for the purposes of establishing or confirming what happened. The nature of memory means that people’s recollections 0f the same event can be very different to one another’s. This is because of naturally occurring differences in the details attended to at the time, as well as differences in each person’s ability to accurately remember those details.

Despite these initial differences in each person’s recollections, a growing body of research shows that when people talk about their memories they can influence each other such that their subsequent individual memory reports become similar to one another’s. This phenomenon is typically referred to as memory conformity. It occurs because people accept, and later report, information that is suggested to them in the course of the discussion. In everyday life, it is often of little concern if people’s memories change and become similar to one another following a discussion. However, there are particular contexts where memory conformity can have serious consequences, such as eyewitnesses discussing their memories together prior to providing a police statement.

When memory conformity occurs in the context of a forensic investigation there can be serious implications. For example, police might mistake corroborative witness statements as being a product of independent witnesses with consistent versions of events, when in fact memory conformity might be responsible for the similarities if there has been some form of interaction between co-witnesses. Given the importance of reliable witness accounts within the criminal justice system system, I have investigated the consequences of witnesses discussing their memories together prior to providing a police statement.

Watch this video to see a demonstration of the memory conformity effect.