Confirmation Bias, Dr. Sherry Nakhaeizadeh

(contemplative piano music) - So where do our beliefs and opinions come from? And how do we make sense of the world that we live in? We like to think that we're able to make judgments and decisions about the world around us in an objective and logical way.

But this is not necessarily the case because of the way that our brains process and store information. In everyday life, we are exposed to a huge amount of information. And this information differs for everybody, because we don't experience life exactly in the same way.

And in order for your brain to make sense of the world that you live in and process all of this information, it will use filters and shortcuts. And this is all extremely beneficial, because that filter will optimize the information processing. Why do we, for example, during election season, only tend to look for information that paints our favored political party in a good light and look for and remember information that will cast our opposing political parties in a negative light?

Regardless of what political party you're voting for, you would never go out and Google negative information about them. This phenomenon is known as confirmation bias, which could be described as the human tendency to selectively gather and process information in order to confirm our assumptions and preconceptions, whether they are true or not. Decades of research within psychology and social science have shown that confirmation bias does not only affect how we gather information, but also how we process and remember information.

The bottom line is that we, as humans, tend to weigh evidence that supports our prior belief to a greater degree than evidence that will contradict them. Everybody is biased, it's just part of human nature. So how does this relate to the criminal justice system and forensic science?

If we take forensic science as an example, one experiment looked into initial exposure to context at a crime scene, to look at whether or not if you're exposed to a certain type of context initially, would that affect how you make interpretations at a later stage? And this specific experiment considered forensic archeology and anthropology excavations where participants were asked to excavate burials with cast skeletal remains that were male and they were dressed in female clothing. And what happened was that the students who excavated the skeleton that had female clothing, later on when they were asked to assess that skeleton, it affected the way that they interpret that male skeleton, compared to, for example, the control group and the people who were exposed to gender neutral clothing.

Showing a difference in the interpretation of that same skeleton. And this is not to say that forensic scientists are bad people doing bad things, but it has to do with the fact that as humans, our brains are subject to limitations. We need to take steps in order to minimize cognitive and confirmation bias in forensic science to the best of our abilities.

One proposed way of doing this is to shield forensic examiners from irrelevant contextual information that could be of a biasing nature. For example, if the suspect has confessed prior to you looking at the evidence, you don't necessarily need to have that piece of information when, for example, evaluating the fingerprint or looking at the skeleton. What happens at the crime scene will follow-up all the way through court.

So if you get it wrong at the beginning, it's most likely gonna go wrong all the way. And taking a more holistic approach to these types of phenomenons is extremely important in order to understand the whole process. It's not enough to simply just have the knowledge of cognitive biases.

Education alone will not combat cognitive biases, but the raw procedures that we could implement within the forensic science process, that could help us minimize and to some extent, control that we don't get affected by these.