Lie detector expert reveals how a polygraph works – as he gives his verdict on The Jeremy Kyle Show’s use of the tests

They feature frequently in real-life murder documentaries and, until 2019 when The Jeremy Kyle Show was taken off air, were a huge focal point for reality TV shows. But what does it feel like to actually take a lie detector test? 

The use of such tests have been under the spotlight in recent weeks as an inquest was carried out into the suicide of Steve Dymond, from Portsmouth, who was found dead seven days after failing a lie detector test on the Jeremy Kyle Show where he was accused of cheating on his partner.

Coroner Jason Pegg ruled there was ‘insufficient evidence’ to suggest there was a direct link between Dymond’s appearance on the show and his death, adding it would be ‘speculative’ to say the presenter, Jeremy Kyle, and his show, had contributed to the death.

However, Mr Pegg said he could not conclude whether Dymond had lied on the test or not. Speaking about Mr Dymond’s case, Jason Hubble, owner of Lie Detectors UK, said he would not have carried out a polygraph test on Mr Dymond.

This week, I travelled two-and-a-half hours to Maidstone, Kent, to Jason’s offices, where I learnt more about lie detectors, the polygraph tests used by them, and the code of ethics lie detectors use to protect vulnerable people. After speaking to Jason about Mr Dymond’s case, I was put in the hot seat myself.

My mission was to find out more about ‘lie detector’ tests, including how they work and their accuracy (Pictured: Maria Okanrende with polygraph examiner Jason Hubble)

Jason, 51, a polygraph examiner for 11.5 years, and whose work has taken him into the minds of celebrities like Davina McCall and rapper Darkoo, Arsenal players and cheating husbands, revealed the tests he carries out are not actually called ‘lie detector tests’. 

He explained that there was no such thing as a ‘lie detector test’, but rather a ‘polygraph test’. A polygraph is a machine in which the multiple (‘poly’) signals from sensors are recorded on a single strip of moving paper (‘graph).

Here’s how it works: When a person takes a polygraph test, four to six sensors are attached to them. The sensors usually record a person’s breathing rate, pulse, blood pressure and perspiration. They can also sometimes measure someone’s arm and leg movements.

Jason revealed that the majority of his work involved infidelity cases, while 25 per cent dealt with theft and other allegations.

But while he revealed that polygraph tests weren’t permitted in a court of law, he claimed it was still an ‘effective interrogation tool when used correctly’ as it often encouraged people to confess the truth.

Crucially, Jason discussed the code of ethics he follows when he’s carrying out lie detector examinations with a polygraph test. 

‘If you had a diagnosed mental illness, if you were taking high doses of certain medication, if we thought there was going to be a threat of violence after the test, we wouldn’t test you,’ he said.

‘Ethically, you have to look at the bigger picture.’ 

Jason added: ‘I wouldn’t have tested Steve Dymond because he wasn’t a suitable candidate for testing.

‘Whether he disclosed that to the Jeremy Kyle show is a different matter. I would guess he probably didn’t.

‘Their aftercare should have been there to look after him personally.’  

A polygraph is a machine in which the multiple (‘poly’) signals from sensors are recorded on a single strip of moving paper (‘graph) (Pictured: the results of my {failed} polygraph test)

I was nervous and continuously took deep breaths hoping to beat the polygraph test

‘When you lie it pushes your body through a very big workout. It’s easy to tell the truth but hard to lie,’ he added.

‘We’re looking at changes in blood flow,’ explained Jason. ‘When I lie, my body will take the blood out of the hands and feet [and] back in [to] the main organs. Very similar to the fight or flight reaction’.

After discussing the details of a polygraph test with Jason, and the use of such tests on The Jeremy Kyle Show, I was put in the hot seat myself to understand how they work; and to determine how easy it might be to cheat on such a test.

Although I had nothing to hide, being strapped to a seemingly endless maze of wires and cuffs, which were in turn hooked up to the lie detector machine, I couldn’t help but feel guilty of something.

On top of the stress it was a cold morning, and I suspect the sudden drop in temperature left me already feeling a little shaky.

Known as the emotional one among my friends, I knew right away that my body would give me up should Jason try and delve into my personal secrets.

‘What are you going to ask me about? I need to know’, I said nervously, trying to mask it with a laugh. 

Jason then revealed that a full and complete polygraph test would take approximately two hours and set me back £399. Therefore he’d prepared a mini version which would utilise the same principles but be less serious in nature.

‘I’m going to ask you five questions and the test will take about five minutes,’ said Jason.

Handing me a notepad and a pen, and telling me to take a seat, he asked me to write down five names; one would be my mother’s name and the other four were to be fake names.

A spider web full of wires marked with different-coloured tags, miniature bits of plastic and a material cuff – similar to the one used to to measure blood pressure – all appeared on Jason’s serious looking desk

Jason explained that he planned to ask me about each name, and whether or not it was my mother’s real name. 

To prove the efficiency of the famous ‘lie detector test’ I was to try and cheat it by never giving up which name was my mother’s. To do this I was instructed to answer ‘no’ to each question.

To be honest, I was excited at the prospect of cheating the test – but my brief spell of happiness subsided once I saw Jason dragging out his polygraph equipment. 

A spider web full of wires marked with different-coloured tags, miniature bits of plastic and a material cuff – similar to the one used to to measure blood pressure – all appeared on Jason’s desk.

He then brought out more bits and pieces, including a black machine with levers, as well as square-shaped sticky pads called ‘sensors’ that were to be plodded on my fingers.

I was getting scared.

‘Is this going to hurt?’ I asked. ‘Not at all. But you may feel slight discomfort’ Jason replied.

Before the test began I quickly scribbled down the first five names that came to mind: ‘Chaka’, ‘Rihanna’ (what I can I say? I’m a fan!) ‘Elizabeth’ (my mother’s real name), ‘Lolade’ (my Nigerian name) and ‘Jessica’. 

The expert said my sweat glands gave me away, and he knew instantly that my mother’s real name was Elizabeth

First he attached a long metal chain and some wires around my upper body, both of which were hooked up to a small black machine and linked to a laptop. He then placed a cuff around my right arm.

‘This is to measure your blood pressure,’ said the expert. He flicked a switch and the material began gripping tightly to my arm. I suddenly felt trapped.

My nerves wasted no time in showing themselves as I quickly began shaking violently. ‘I’m going to ask you not to move,’ he added.

I vaguely recall him telling me once more to keep still, but at this point it was clear I had lost all command of my body. 

The decade-long expert offered some words of encouragement and told me to stay calm, even pausing the test until I felt better.

Jason has been a polygraph examiner for 11.5 years. His exciting work has taken him into the minds of celebrities like Davina McCall and Darkoo, Arsenal players, and cheating husbands

Once I heard the words ‘this test is about to begin’, I knew there was no escape.

Jason continued: ‘Do not move. Answer “no” to each question including to your mother’s name’.

Suddenly Jason had transformed into an official polygraph test conductor and I immediately felt myself melting under the weight of a lie I had not yet told.

‘Is your mother’s name Chaka?’ asked Jason. Before answering I took a deep breath and tried to employ my best poker face. ‘No’ I responded.

I used the same tactic when answering each question, ever so sure my smooth ways would hide the secret of my mother’s name.

As quickly as it began, it was soon over. Jason turned to his laptop and told me my ‘sweat glands’ were overworked during the entire test.

To be honest I had felt sweat dripping under my make-up but tried my absolute best to remain calm.

Giving a review of the results, Jason said: ‘We’re going to look at sweat gland activity. It’s about 40 per cent of the overall mark.

‘The first question “is your mother’s name Chaka?” [Here] we’re hitting 65. The second question, “is your mother’s name Rihanna?” We’re getting 80.

He then paused before announcing that he had in fact caught my (weak) lie.

‘Look at the third question when we say “is your mother’s name Elizabeth?” There’s a big jump! Look at your blood pressure! It’s the only question where we’re seeing massive great rises’.

With an all-knowing look in his eyes, he finally asked me: ‘Is that the question that you lied to?’

With a big smile I confessed: ‘Yes, that is her name’.

Jason, thank you for the experience but if I commit a crime I’d rather just confess. I never want to go through that again.