Everybody lies, and we don’t need a lie detector test to confirm it… That is why for centuries, humanity has been trying to find a means that can identify this lie.
Search methods evolved from simple eccentricities to terrible torture until the polygraph was invented in the 20th century. But is a person so simple that only a machine that reads the pulse is needed to solve it?
Types of lie detector test
1. Scary to imagine
Yes, intimidation was the favorite method of searching for the truth in antiquity. The inventiveness of our ancestors is amazing today. But all the maneuvers came down to one thing: to achieve a certain reaction of the body to the stress caused by psychological stress.
2. Rice flour or grains
A popular technique for calculating a liar in ancient China was the use of rice grains or flour. During the hearing, rice was poured into the suspect’s mouth. After the inquiry, the contents were taken out of the defendant’s mouth: if the rice is dry, you have a criminal in front of you because, during stress, the amount of salivation decreases. Why be afraid if you’re not guilty? Later, the Spaniards and the British borrowed this technique, replacing rice with bread.
3. Stroke the donkey’s tail
This “harmless” check is cunning and multi-leveled. In a dimly lit room, the suspect had to stroke a donkey’s tail. Before that, he was told: “if you stroke the donkey and he screams, you are guilty, if not, you will be free!” In fact, the donkey’s tail was smeared with paint. The involvement of a person was determined not by the cry of the animal, but by the cleanliness of the hands of the alleged criminal: the guilty person would be afraid to stroke the animal so that it would not scream.
4. Broom method
The broom, a common cleaning tool? No! In several African countries, and for generations, it is also used to disentangle the truth from the lairs. And at this little game, this household utensil, which is also a strong social symbol, seems infallible. If it may vary slightly depending on the country or person, the method is quite simple. For example, assuming there are several suspects, you have to take them individually, make them swear on two brooms, and pass the brooms around each person’s neck simultaneously.
However, for the innocent, nothing happens, but on the turn of the culprit, the vise inevitably tightens on his or her neck and loosens only when the fault is confessed. Most often, the culprit receives punishment according to local rules.
5. Egg with fragile shell
In Africa, it was believed that a tremor would betray the culprit. The defendants had to pass a fragile egg in a circle. The one who could not cope with the excitement and trembling in his hands crushed the egg.
Spartan warriors were known for their bravery in battle. But only the best of the best went into battle. Before starting training, potential heroes were placed on a cliff and asked if they were afraid or not. Of course, most often, the answer was negative. But the unprepared were calculated by the pallor of the face.
Only the person who turned purple at uncomfortable questions could become a bodyguard in ancient Rome. Such a person will not be able to lie and betray.
The famous Roman “lie detector” – “Mouth of Truth”. The person who was suspected of lying had to place his hand in the “mouth” of the sculpture of Triton and answer the questions asked. According to legend, if the suspect lied, the deity would bite off his hand. Nobody wanted to take risks. Moreover, there is information about the executioner, who cut off the hand of the guilty in the presence of evidence.
7. Gong strike
In ancient India, they monitored the strikes of the suspect in the gong. He was asked a series of questions about the crime. The potential criminal had to answer the first thing that came to mind, and at the same time, beat the gong. If the rhythm of the beats changes – the subject is a liar!
8. Hands-on the pulse
A physician from Persia, Avicenna, offered to “catch” unfaithful wives by measuring their pulse. Women who were suspected of betraying their spouses were given male names. At this time, the doctor recorded the pulse rate. It was believed that on a “certain” name, the pulse should have quickened.
Eight centuries later, Daniel Defoe, in 1730, proposed using this method to expose a liar: fear and guilt accompany each other. The first principles of lie research became clear in the 18th century, it’s time to tackle the technical side of the issue!
9. Creation of a polygraph
It took about 150 years to determine the relationship between plethysmograph readings (a device that measures the pulse and changes in fluctuations in vessel volumes due to blood filling) and stress. The scientific study was carried out by the Italian physiologist Angelo Mosso, who did not even think of applying his knowledge in forensic science.
But a few years later (1881), the famous Italian psychiatrist and criminologist Cesare Lombroso began to apply this discovery at inquests. Hydrosphymograph – the first lie detector. He recorded changes in the suspect’s blood pressure.
In 1895, Lombroso wrote the book The Criminal Man, in which he described a case from his practice: when a suspect was asked questions about an alleged theft, his pressure was unchanged. But when the man was asked an extraneous question, his pressure rose sharply. It turned out that the suspect did not commit the first crime and was calm, but the following questions unsettled him and led him to another crime – the theft of passports.
It is wrong to think that forensic science is only about proving guilt. Facts are important here, and they do not always point to the guilt of the suspect. So in 1902, for the first time, with the help of a plethysmograph, the innocence of a person accused of murdering a 6-year-old child was recorded! Later, the investigation confirmed this “verdict”, and the case was closed.
10. Lie detector
The search for the truth was continued by American psychologist William Marston. During the First World War, he measured the pressure of 70 potential German spies. Based on these data, he was able to calculate the criminal, and he was caught red-handed: theft of secret documents for transfer to German agents.
The idea to come up with a device that detects the presence of untruth occupied the American psychologist and inventor William Marston, who later became just a pop star in psychology. This man is one of the few who was not connected with the police or intelligence. He often collaborated with advertisers such as Gillette; gave an interview to Universal, and then completely influenced the creation of Wonder Woman.
But we are interested in another episode of his biography. At a time when Martson was working on his dissertation on detecting lies by the force with which oxygenated blood is sent from the heart through the body (systolic pressure), he took out a loan for the creation and development of a device called the “lie detector”. It is under this name that this device will be presented in the press, after rumors about successful research have spread. It was the first device to record changes in blood pressure at the time of the survey.
11. Just “Polygraph”
For many years the term “lie detector” has been used for marketing purposes. The term itself is not entirely accurate: the device never registered the presence of a lie, but only showed changes in the subject’s body during the study.
In 1921, a freelance police officer from America, John Larson, created the first successful prototype of today’s polygraph. The device noted changes in three indicators at once: respiration, pulse and blood pressure. The term “polygraph” was also given to the device by Larson, although in the last century this word had a different meaning.
In 1923, the Americans, for the first time, conducted such an examination right in court.
Leonard Keeler, in 5 years, upgrades the teacher’s device (Larson). Despite the fact that the polygraph was often used by the police, Keeler decided to make it portable and add an element of recording skin resistance (CNS response to a stimulus, i.e. a question). Later, another parameter was added – tremor. All these parameters are basic in such an examination today.
Keeler solved about 800 crimes, patented the device and founded the first school that uses the method of calculating hidden information.
The question would be logical: if everything was so glorious back in the 30s of the last century, why does the polygraph do not suit us today? Why do criminals escape punishment?
12. Neuroscientists versus forensics
Despite this technological breakthrough, many questions remained in research on lie identification. Doctors and scientists did not trust the data of the polygraph throughout the entire period of its development. And this criticism has only grown stronger every year.
The main problem of the polygraph is the study of the truth by the physiological reactions of the body. But psychologists inform that there are no reactions that can indicate that a person is lying. And the polygraph registers the result of excitement and fear during the procedure, i.e. these feelings can be experienced by ANY person, regardless of his involvement in the crime.
The result of the study is influenced by a number of extraneous factors: the competence of the researcher, his personal attitude towards the subject, and vice versa, how the suspect relates to what is happening and the accusation in general (he may not remember anything, but memory will complete the story for him). Physical condition (presence of chronic diseases and problems with the heart and breathing, pregnancy, use of drugs) also affects the result of the test.
False “evidence” often ruins the lives of innocent people. The high-profile US case of the 2000s: worker Emmanuel Marvelous was accused of robbery and attempted murder. The accusation was erroneous, and the man, confident in his innocence, himself offered to be tested on a “lie detector”. But before the procedure, grief happened: Emmanuel’s mother died. His shock could not but be reflected in the test scores. The man was charged under the presented articles for 11 years, and the data of the examination played a significant role. Only after 3 years of imprisonment was it possible to challenge the verdict.
Emmanuel Marvelous was indicted in 2008, despite the fact that five years earlier, the US National Academy provided evidence that most lie detector tests are UNRELIABLE!
Finding truth today
Today, in some Western countries, an examination conducted on a polygraph is not evidence in court. A person, in principle, can refuse to pass it.
Despite the growing distrust of testing, polygraphs continue to be used. And even if many private companies are prohibited from using the device when selecting candidates for work, this does not stop them.
Artificial intelligence and the polygraph
Many companies from various fields of activity (developers, realtors, banks, writers) today use the possibilities of artificial intelligence. So why not direct his “talent” for the benefit of mankind and put an end to the history of the definition of lies and truth?
There are those who are not afraid to make loud statements. But is there a result? The creators of Silent Talker Lie Detector offer a program that studies a potential criminal by 40 indicators: head tilt, changes in facial expressions, blinking speed. Then she compares the result with a special video, looking for connections that a person cannot see.
But there are two controversial points: 1. A small number of subjects; 2. The relationship between deception and facial expressions does not have 100% evidence.
Programs and applications of other companies are also based on the mimic changes of the suspect, the movement of his pupils, and even the change in the timbre of the voice. But all these studies have no evidence base.
But who knows, maybe these searches will lead humanity to the truth. Everyone wants the interlocutor to be as sincere as possible with him. Unfortunately, people are not always honest in life.