Winston Churchill once famously mused that democracy is the worst form of government except any other, and in recent years, studies into the accuracy and reliability of eyewitness testimony seem to make a similar point about the use of witnesses to establish a narrative of events. The fact is, though, that we do have several other key tools that can be used to corroborate eyewitness testimony and to test its accuracy, and as they become more and more sophisticated, the shortcomings of eyewitness testimony begin to become clear.
Memory is actually malleable
In a talk that was reprinted in the Stanford Journal of Legal Studies, two professors discuss the history of research into eyewitness testimony and its implications. Among the highlights of their finding, there emerged a stark set of facts:
- Elizabeth Loftus's slide experiments showed how easily false memories could be introduced by third parties in the early 1970s, and the body of work has grown since then.
- Subsequent studies have shown that the adjustment of memory due to external influences is actually healthy and necessary, meaning that managing memory effectively could mean changing it over time.
- Memory is affected by retelling, and changes with multiple retellings even if there is no outside influence intentionally introducing false memories.
- The complexities of these mental functions lead experts to question the idea of an "original" or "unaltered" memory.
Putting it all together, it seems like the research points to the idea that eyewitness testimony is actually incredibly unreliable, and so it is not as useful as physical testimony. Believing that would be an oversimplification, though.
Weighing evidence against eyewitness testimony
When it comes down to it, eyewitness testimony is not going to be the strongest form of evidence unless it can be corroborated. Where it becomes powerful is when it is brought together with physical evidence in a way that explains the physical evidence rationally and without too many inconsistencies. It's also important to understand when memory is likely to be more or less accurate. Events that people play active or central roles in, testimony about people that are known to them, and other active eyewitnesses tend to be overwhelmingly accurate compared to bystander eyewitnesses and those who only observed the event from a distance or who were focused on their own affairs at the time.
Witnesses and criminal proceedings
In many cases, there are good reasons to question eyewitness accounts of individual events, especially when it comes to events that played out quickly over a short period of time. The science is clear: memory is simply too malleable and too easily biased for it to be considered the highest quality form of evidence. It can still be powerful, though, and just because it is prone to mistakes does not mean that it is going to become less central to the criminal justice system. Questions about the usefulness of eyewitness testimony in a legal scenario should be discussed with a qualified attorney.