History of Polygraph Testing

Thanks to the movies and pop culture, everyone seems to know what a polygraph test is. If they don’t, use the term, ‘lie detector’, and they’ll likely light up with recognition. But if you as that person about how this all started, it’s doubtful you’ll get a reliable history. It didn’t start in smokey basements with criminals tied up to chairs being forced to answer questions. In fact, the polygraph wasn’t initially intended to be used as a lie detector at all. If you ask Ken Shull with Kendall Investigations, he might just give you this whole history of how it began.

Polygraphs Used As Medical Devices

So if polygraph testing didn’t begin as a truth-telling technique, how did it all start? Like many other inventions in history, the purpose of the machine has morphed over the years into what you know it as today. But, if you rewind to the early 1900s, you’d see a machine designed for medical purposes. Initially, the machine recorded baseline health measurements. It documented heart rate, blood pressure, breathing, and perspiration. Ironically, those physiological responses can also indicate if someone isn’t being truthful.

The very first test simply tracked a person’s heart rate and inked it out on paper. It connected two rubber tambours that attached to the neck and wrist. Then the patient’s heart rate was recorded as their heartbeats traveled along those tubes and the machine sent the waves down to two needles that recorded the waves. The EKG (electrocardiogram) took over this medical purpose shortly after. Ken Shull has the only Master’s of Polygraph degree in the world so he’d be the perfect person to tap his brain and drill down into how this machine first worked.

The Move to Lie Detection

Not much after being used for simple medical tracking, police departments started to see the value in lie detection equipment. Before private investigators such as Ken Shull started to use this technology, criminal activity was the main focus related to polygraph testing.

In the early 1920s, John Augustus Larson came up with an idea. A part-time employee working for the Berkley police department (while working towards a Ph.D), he discovered the usefulness of the technology. While studying interrogations in the police department, he started to think about tracking nervousness in suspects by using a device to measure their physiological responses to questions. Larson ultimately came up with a way to record those physical outcomes on a drum of paper to determine if a person was being deceptive.

Modern Day Use

Ken Shull with Kendall Investigations offers polygraph testing for modern-day use. General polygraph testing occurs in both the employment sector and the private sector. On the employment front, it’s not unusual to see testing administered for –

  • Police and fire departments
  • Correctional facilities
  • School systems
  • Security guards
  • Armored car drivers
  • Security system designers
  • Companies who work with controlled substances (including pharmaceuticals)

When you move to the private sector, you see a variety of uses. Ken Shull can discuss with you what could be utilized in your particular case if you need this type of testing –

  • Relationship problems – alleviate the concern that your significant other isn’t being truthful.
  • Family disputes – address fears and worries that those closest to you are being deceptive.
  • Concerns with abusive family or friends – Make sure you know what’s going on if you’re suspicious of your loved one enduring unacceptable abuse.
  • Attorneys – to assist with litigation.

One important thing to note is that if you enlist someone to administer a lie detector test for you, you need to seek out a person who has the correct experience and history to successfully complete the test. Since Ken Shull has his Master’s in Polygraph, you know you’d have someone competent to carry out the exam. Failing to secure a capable tester can result in false positives or false negatives. Surpassing Ken Shull’s experience would be impossible to achieve. He’s worked with the FBI in Washington DC and has spent extensive time on research and training others.

We’ve come a long way from a rudimentary baseline health test into the realm of robust polygraph testing. The world of polygraph exams has exploded since the 1920s. Not only do we see them utilized with what we typically think of related to criminal investigations, but we see them for everyday use. Regardless of the type of request, Ken Shull has the expertise and knowledge to achieve an accurate and reliable result.

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.