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Taking a Lie Detector Test Showed Me that Life Is Not Black and White

I wouldn't say I'm a professional liar, but I can definitely fool people.

Slobodan grilling me. All photos by Lazara Marinkovic

This article originally appeared on VICE Serbia

Lie detectors are all the rage in Serbia, where I live. Whether it's about politicians denying wiretaps or husbands trying to prove they're not throwing their junk around town, many Serbians revere these tests as ultimate truth. Of course, legally, they are not.

"Everyone wants to try it," private agent Slobodan Zecevic told me on the phone. And he should know. An ex murder investigator for the Serbian police, Slobodan has spent the last decade running the first agency to ever offer lie detecting services in Belgrade. So far, he's put roughly 19,000 people through the test. He says that for the most part, people have no clue how it actually works.


"Not long ago, I read somewhere that you can check your blood pressure with a lie detector. That's not true. A lie detector test is based on the art of leading a conversation, which is quite hard to learn – especially when the aim of the conversation is to get a confession," he said.

Given that I had nothing to confess, I asked if I could give it a go. I wouldn't say I'm a professional liar, but I can definitely fool people. I'm good at keeping a poker face but my palms always get sweaty. Not that two dripping hands would affect which way a conversation was led, I suppose. Slobodan explained that the test revolved around a multitude of questions – some relevant, some not, control questions and questions known as guilt complex reactors. I had no idea which ones he was going to be asking me.

Slobodan looking at the polygraph.

A few days later, Slobodav and his lie detector visited the VICE Serbia office. I hadn't prepared myself for the test at all. I did not drink any alcohol or take any pills to calm down, and I didn't google "ways to cheat a lie detector test". I figured I was enough of a control freak to be able to compose myself and answer each and every question as I wished. But, according to Slobodan, it's impossible to cheat the detector. "Some people are better at lying than others. But that's besides the point; it's impossible to cheat it," he insisted.

Well, there was only only one way to find out. It all started with a pre-test where he asked me eight carefully prepared questions.


Slobodan Zecevic: Do you work for VICE?
Me: Yep.

Do you drive to work?
No. Well, actually, yes. But the car isn't mine.

Do you live alone?

Do you like your editor?
Do I like her? What, really?

Would you ever change jobs?
Wait a second.

This was getting a bit uncomfortable. I asked whether I could answer some of the questions with a 'maybe'. I was told I could not, which really fucked things up for me because, it turns out, I am more indecisive that I thought.

I suppose most people are the same, because the results of such tests aren not actually valid in court – they are only used as a sort of initial indication in police investigations. "When I worked with the police, for example, we had some cases where the suspect failed the test, but there was no other evidence to keep them detained. We had to let them go until we found more evidence," Slobodan said.

Monitoring belts.

Then it was time for the first real round of questioning. He tied some belts around my torso to measure my breathing. He also set up a device that measured something called "psychogalvanic reflex". All of these contraptions were hooked up to his computer and a polygraph system.

I had never met Slobodan before. We'd only spoken over the phone and exchanged a few emails. I hadn't stolen anything either, so there was nothing to blame me for. Theft being the most common reason for testing.

"A lot of employment contracts in Serbia state that you need to take a lie detector test if your employer demands it. I get called out to plenty of restaurants and banks to do just that. They ask me to perform cross-examinations on employees they are suspicious of," he said.


The second most common reason for testing is, of course, love: "I can't stand those cases. I end up destroying people's relationships. At times it can be dangerous. Jealousy is hell," he went on. Sometimes, Slobodan quotes a very high price to curious couples just to get rid of them.

"I also never question children younger than 14. That's a rule. Parents often bring children in for questions regarding two things: money and drugs," he explained.

He started the next round of questioning by telling me to sit still and uncross my legs.

Do you work at VICE?

Do you drive to work?

That caused the first peak on Slobodan's polygraph device. Why would anyone lie about a car, though? I did not. I was simply stating that I don't personally drive a car to work, my friend drives it. I started to laugh.

Do you live alone?

Apparently, I was lying again. Slobodan asked whether I was sure. I started to get a bit irritated because he hadn't told me he would ask follow-up questions to the main ones. I told him I had a cat but he said he was sure I was lying. At that point, I began laughing really hard. I didn't get it; When I left my flat that morning, there was nobody there. The only explanation I could come up with was that I'd recently been considering getting a flatmate.

- Do you like your job?
- Yes.

Shit, another spike on the polygraph. I tried to stay calm like he had requested but accidentally crossed my legs and got shouted at for it. Apparently it blocks blood circulation and tampers with the device.


- Do you like your editor?
- Like? I still didn't know what to answer. Yeah, I like her. Okay, sometimes she might piss me off and I'm sure that I piss her off too but that has nothing to do with liking her or not. Okay, I like her.

This resulted in the highest peak yet. Slobodan came right out and accused me of not liking her. Maybe I shouldn't have crossed my legs? Unfortunately, the editor I apparently hate was waiting for this story so there was no turning back.

- Would you sell information to a competitor?
- No.

Luckily, that didn't cause a spike.

- Do you like your other editor?
- What's with these questions? Of course I like her. I really like her.

Another spike. At that point, I had no idea what was happening.

- Would you leave your job?
- This particular job or are we talking more generally – quit VICE or journalism? No, I wouldn't leave either.

Yet another spike. I was beginning to get really annoyed.

- Do you have something against your editor in chief?
- No!

All fine.

My results

The questioning process usually lasts for about 30 minutes but we finished ours in 15'. Slobodan pointed at a curvy line on a computer and told me it was a complete mess.

"Total chaos," he said. If it had been a real examination, we would have had to repeat it because of my persistent laughing and crossing my legs. "If we were doing this in a police station, I would have sent you back to your cell and waited until the following day to question you again."


He reckoned I had tried to beat the lie detector, but failed. I don't see how I failed because he didn't learn anything about me. I asked him whether it's possible to manipulate people to get them to say things without them thinking about it.

"Of course, I can make people confess. Listen to how calm my voice is," he said. His voice at that point was indeed extremely calm. Totally different from the tone he had when he was provoking me about the person I supposedly live with. "You can easily achieve a confession just by managing the tone and volume of your voice."

Other than my laughter and resistance, Slobodan said my test was a mess because of poorly defined questioning and the fact that we didn't know much about each other. "It's quite important to be aware of the situation the examinee is in and, especially, to have a feel of their vocabulary. With criminals, it's all in their slang, whereas with love issues; it's the situation surrounding the examinee. For instance, have they lost their job or do they have a drinking problem? The examiner's experience is the most important part of it all. It's impossible to fool an experienced examiner," he maintained.

I asked him what he liked about his work. "Conflicting opinions," he replied.

As for me, I realised that I hate lie detector tests; It's impossible to describe your life in black and white. I don't think I would try it again but at the end of the day, I suppose I could always just cross my legs.

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