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Bringing Science into the Interview Room

A few hundred years ago, the determination of innocence versus guilt was conducted in some questionable ways, often known as a “trial by ordeal.” In the Middle Ages, one way to determine guilt in a theft investigation was known as “trial by water.” The person under suspicion would be simply bound up and thrown into a body of water—the guilty would float and the innocent would sink. As an obvious lose-lose situation, neither option seemed to be beneficial for the accused person.

This is obviously a terrifying way to conduct an investigation, but at the time it was being used this was accepted and normalized. Most people would accept the outcome of the test and assume it was an accurate determination because that’s what they had come to know, and it was being conducted by people of authority.

As we fast-forward through history there have been multiple progressions to this antiquated process including “trial by fire,” the rice method, third-degree tactics, polygraph testing, and behavioral analysis. Each of these methods had, in its time, been accepted as accurate ways of identifying the innocent from the guilty.

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How Do You Know What You Know?

This question is the root of the point of this article—questioning why we do what we do or how we know what we claim to know. For the spectators of a suspect floating in a pond, they believed this person was guilty based on what they were told to believe or even more convincingly, it was proven that the person was actually guilty, and the test was therefore, accurate. Bringing this to modern day, we fall victim to this same philosophy in a variety of circumstances.

Let’s think about detecting deception. As kids, we most likely thought that liars’ noses grew as they fabricated their story because we learned our lessons from a person of authority—Pinocchio. Or our parents routinely taught us to “look them in the eyes” when we tell the truth, which would obviously suggest that a liar must avert eye contact. These beliefs then are reinforced by movies and TV shows, such as the Law and Order interrogation scenes or the psychological thrillers where the suspect was identified through an expert in behavioral analysis. Even more convincing is when we suspected someone of lying because of these behavioral “tells,” only to be confirmed by additional evidence that they were, in fact, guilty. This confirmation of our suspicion only further validated our original hypothesis.

However, these situations are all unique and not necessarily generalizable or accurate. Yes, John Doe happened to sneeze everytime he lied, and Suzy Smith rubbed her neck whenever she was deceptive, but what about the suspect who has allergies or the victim who has a sore neck? Bringing science into the interview room doesn’t mean we have to wear a lab coat and bring out the test tubes and Bunsen burners. But we should use the scientific method to question accuracy, reliability, and replication.

Testing the Status Quo

Science may seem intimidating for those who are having flashbacks of chemistry and biology class, but the scientific method is actually something we use on a daily basis. The concept of this method is to guide our decision-making process through research, testing, accepting errors, modifying, and testing again. If we consider our analysis of Suzy Smith rubbing her neck, we should be skeptical that it is directly associated with deception and that it is generalizable to all other suspects.

To make this simple, we can visit a topic of equal importance— desserts. Many people have recipes passed down from generations that produce a delectable treat. These treats, proven to be good through years of “taste testing” produce a reliability in the process that made them. However, the first time you attempted to make the same dessert in your kitchen, it likely turned out different. If you used the same exact process, followed the recipe exactly, how could this be? We must consider the variables. Was it a different brand of flour? Different oven? What was the humidity in the house? Did the dough sit out too long? The problem with this perfect recipe is that it seems to only work best with the same baker, in the same kitchen—it’s not generalizable.

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Now that you’re hungry, let’s discuss how this translates to interviewing. If we revisit the case of Suzy Smith rubbing her neck when she is being deceptive, we would have to test several variables to see if this is an accurate way of detecting deception—for Ms. Smith and for the rest of the similar population. In a hypothetical test of liars and truth tellers, we would most likely see several people rubbing their neck with no direct correlation to deception. We could also see people averting eye contact, fidgeting, or coughing. These symptoms, however, could be a result of anxiety or nervousness unrelated to guilt. Even further from deception, maybe a subject has a sore neck from sitting at the desk all day, or they are fidgety because of stress at home. Although this is obvious from an outside perspective, our biases often fall back into place during an interview. We often have a belief on how liars respond, and when we see these cues, it only confirms our initial belief. But this is not science, and this is dangerous.

How Does This Impact Me?

The scientific method consists of seven steps:

  1. Ask a question
  2. Research the topic area
  3. Establish a hypothesis
  4. Test the hypothesis with an experiment
  5. Make an observation
  6. Analyze the data
  7. Report your conclusions

This is not to suggest that each investigator must be an expert on the scientific method, but we should be skeptical and question our assumptions. Frankly, this is how an investigation works anyway. We gather evidence, question the evidence, search for more information, analyze that information, report the details, and then cycle the process.

Practitioners should take this approach through every part of the interview process. Why do I develop rapport? What is the purpose of asking open-ended questions? How do I tell if someone is being deceptive? The answers to these questions should not be base off claims of “That’s how I’ve always done it,” but instead we should challenge the reasoning and understand the application of empirical data.

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Evidence-based methods are rooted in the scientific method, open to fallibility, and demand to be continuously challenged. Interview training is no different, this thought process is what drives change and produces more relevant, credible tactics to implement. Start asking questions, understand the variables that may impact the results, and make sure to write down that cookie recipe. You’ll get it right, eventually.

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