What You Need to Know Before Taking a Polygraph Test

For most people, the only experience they have with polygraph testing is what they have seen on TV. That means that when they are finally faced with a need to take one themselves, they may be feeling incredibly nervous about the entire process. However, it is not as scary as it seems! They are not just about proving criminal activity; they are used in many different situations outside of a criminal investigation. In fact, many people routinely sit polygraph exams as part of their employment. As one of the premier agencies offering Polygraph in Knoxville, TN, we are here to share a few things you need to know before taking a polygraph exam for whatever reason.

Stick to Your Everyday Routine

We have learned in our years of administering Polygraph exams that there are a lot of myths surrounding the process. For example, many people are afraid that something like caffeine or medication will impact their test accuracy. That is certainly not the case. If you are someone who likes a cup or three of coffee in the morning, go ahead and drink them on your exam day. It’s likely more harmful to skip them as you will put yourself on edge.

Similarly, if you take daily medications, please continue with that as directed by your doctor, although we do ask that you disclose pre-existing medical conditions. The exception would be if you are pregnant or are suffering a short-term illness like cold or flu. In those situations, we would ask that you reschedule your booked polygraph in Knoxville.

Don’t Overthink Your Answers

When you have a polygraph in Knoxville, you are primarily going to be answering yes or no questions. Try not to overthink the questions; answer truthfully. Some people think too hard about the question and start to doubt themselves. The test doesn’t pick up ‘maybe,’ so relax and stand firm on your answers. If you are honest, you shouldn’t need to deliberate on the answers. Before your exam, your polygraph examiner will already have spent time talking to you and discussing the test, so you should hopefully be relaxed and prepared.

Don’t Try to Beat the Polygraph

Many people come for their polygraph in Knoxville and attempt to control their breathing, slow their heart rate, and other tricks designed to beat the machine. Most of these people end up with a fail even though they were telling the truth! All of those tips and tricks out there on the internet for beating a polygraph simply do not work, and attempting them just messes up your readings. At Kendall Investigations, our examiners are both former FBI agents who worked in the polygraph division. Our founder Ken Shull is the only person in the world to hold a Master’s Degree in Polygraphy, and he was head of the entire FBI Polygraph department for many years. In short, we have the experience and the skill to spot a cheat a mile away.

Uncover the truth!


Ken Shull served as a Special Agent with the FBI for almost 25 years and was head of the FBI Polygraph program until his retirement in 2001. At that time he set up the Kendall Investigations practice as a private investigator in Knoxville, TN offering Polygraph services, private investigations, and security guards. Ken is a member of the American Polygraph Association and The American Association of Police Polygraphists.

The Truth is Still the Truth Even if No One Believes it, A Lie is Still a Lie Even if Everyone Believes it.