Memory is a fickle thing. When meeting someone for the first time, someone might feel certain they have met the person before. Or, they might have met someone briefly but do not seem to remember him or her on a second encounter.
These occurrences are minor inconveniences in daily life, but the failure to accurately remember faces leads to much graver consequences in the realm of eyewitness testimony, as Dr. Nancy Franklin, associate professor of cognitive science at Stony Brook University, explained.
Franklin and collaborators recently published a paper highlighting the factors that play a role in identification and memory of criminal events. Even under ideal conditions, they found that people correctly identify unfamiliar faces only about half of the time.
This percentage further decreases when weapons are present or under stressful conditions, which are common characteristics of crime scenes. For example, in a study conducted by the U.S. Military, high threat and low threat training environments were created, personnel were divided equally between the two and then they were interrogated for 40 minutes. When the personnel were then tasked to identify the investigator, those in the high stress environment made correct identifications only about 30 percent of the time and were twice as likely to make a misidentification, even after 40 minutes of direct exposure.
A myriad of studies have corroborated these results and questioned the validity of facial recognition, yet the general public continues to view eyewitness testimonies as reliable evidence.
“The biggest problem is that people don’t recognize that it’s a problem,” Franklin said. She continued by saying people believe that they will never forget the details of a life-threatening experience. Flashbulb memories are perceived to be highly accurate and people place a large amount of confidence in them. In actuality, Franklin found a “low correlation between confidence and accuracy.” Franklin further explained that historically, 78 percent of cases in which people were exonerated had used eyewitnesses to convict the people. These statistics strongly suggest the inaccuracy of memories, which is partially due to the vulnerability of memories to change.
In an experiment Franklin explained, individuals were shown mug shots of suspects. One of the suspects whose mug shot was shown was then placed in a line up with different suspects. Due to the mugshot exposure effect, the individual is much more likely to pick the suspect that appeared twice, in the mug shot and the lineup, due to increased familiarity and exposure to that suspect. Therefore, multiple identifications of a suspect may not be as accurate as previously thought, because the brain is choosing based on familiarity and not memory.
Furthermore, memories can be easily distorted by outside information and other input as the human brain strives to create a complete model of any event. Studies referenced in Franklin’s paper found that talking to other individuals about a crime or interpreting the behavior and social cues of a police officer presenting mug shots can alter a memory.
Even with surmounting evidence against the validity of eyewitness testimonies, “jurors still use eyewitnesses as the most important tool to make a decision,” Franklin said. The powerful, emotional and confident identification of a suspect by a witness who was at the crime scene is difficult for most jurors to question. Franklin hopes however, that through papers she has published and news reports that highlight stories of those who have been exonerated, the general public will be more aware of the inaccuracies of eyewitness testimonies, ultimately leading to rightful convictions.
