Most people don't like to be wrong. That's why we tend to seek out and read new information in a way that reinforces our previously held beliefs, and we disregard evidence that our beliefs are mistaken or wrong. This phenomenon is known as confirmation bias. At best, it can keep us from learning new things or changing our minds. At worst, it can have catastrophic consequences for ourselves and others.
Nobody likes to be wrongfully convicted. And, according to a new study, many people who've been wrongfully convicted are victims of confirmation bias. But what can be done about it?
Texas State criminologists Kim Rossmo and Joycelyn Pollock analyzed 50 wrongful convictions and other criminal investigative failures to find out how these errors keep occurring, and focused on confirmation bias and other thinking errors as major causes. In fact, confirmation bias, even more than flawed forensics or improper interrogation techniques, was the most common cause, present in 80 percent of wrongful convictions that the researchers studied.
"In an ideal world, we would make the best possible decisions after a careful evaluation of all available evidence. Judgment, however, is often impaired by cognitive biases. Within the context of a criminal investigation, such systematic errors in thinking can result in an unsolved crime or a wrongful conviction; our study found confirmation bias, in particular, held a pivotal position in the causal structure of wrongful convictions. Faulty assumptions, probability errors, and groupthink often played supporting roles. Cognitive bias affects not just investigators, but also prosecutors, defense lawyers, scientists, military leaders, politicians-indeed, everyone."
As for how this might play out in a criminal investigation, Rossmo and Pollock point to Jon Gould's research on erroneous convictions:
"An officer may be so convinced of an eyewitness's identification that he ignores other case facts that point away from the suspect's guilt; a forensic scientist may conduct a hair comparison and see such a close match between that of the perpetrator and a suspect that he overlooks fingerprint analysis that isn't as compelling; a prosecutor may be so satisfied with a suspect's confession that he discounts forensic evidence that inculpates others..."
These are massive issues in the criminal justice system. Not merely for the negative effect they have on the system's integrity, but the more personal and painful effects on those wrongfully convicted, who may spend decades or their life in prison based on others' confirmation bias. "Innovative and effective methodologies are necessary for both problem analysis and solution generation," the study concludes. "Detectives must minimize the risk of error by accurately assessing evidence reliability and avoiding premature shifts to suspect-based investigations."
It also means criminal defendants -- and their lawyers -- must be especially aware of these pitfalls, and be ready to point them out to investigators, and potentially to juries. If you've been charged with a crime, contact an experienced criminal defense attorney right away.