Forensic psychiatrist reveals the truth about whether lie detector tests are accurate and reliable

An expert has discussed whether polygraphs – also known as lie detector tests – are actually effective when it comes to detecting cheating.

Dr. Sohom Das, 44, is a forensic psychiatrist based in London. He is also a YouTube content creator and runs a channel called A psych for painful minds.

There he covers a range of mental health and crime topics, as well as commentary on news and culture issues.

In his YouTube biography, he is described as a professional forensic psychiatrist and expert witness who discusses his own (anonymized) real-life cases.

In addition, it reads: “Dr. Das (MBChB, BSc, MSc, MRCPsych) has ‘personally assessed hundreds of patients in prisons and secured locked psychiatric wards and courts across the UK.’

Are polygraph tests reliable? The general consensus is that they are ineffective when it comes to detecting cheating (stock image)

In a recent video titled Are polygraph tests accurate or reliable enough?he discusses the devices.

Some people and organizations argue that polygraph tests can have a very high accuracy when it comes to showing whether someone is a liar.

However, polygraphs largely fell out of favor in the field of deception detection in the early 2000s.

Polygraph tests measure the fear-based arousal that a person will show when answering crucial questions.

These physiological markers include things like sweating.

The idea that these characteristics will change during lying is based on the premise that fear of deception increases due to the liar’s fear of being caught.

In his video, Dr. Tie this out.

He says: ‘The biggest problem with the polygraph test is that they are not accurate and only measure anxiety, as opposed to measuring people who are actually lying.

HOW DO LIE DETECTOR TESTS WORK?

The polygraph, the most commonly used lie detection instrument, assumes that the body responds involuntarily to the stress of lying.

It measures responses such as changes in skin conductance, heart rate, blood pressure and respiration while the subject is asked a series of questions.

Using a number of sensors attached to the body, physiological changes can be used to determine whether someone is telling the truth.

A major change in any pattern, sometimes called a “response conflict,” is considered by some to be a sign that someone is lying.

‘The polygraph will measure biological processes to determine whether the subject is experiencing physiological events, such as an increase in blood pressure or an increase in heart rate.’

Researchers have said this doesn’t prove someone is lying, because liars don’t necessarily show greater signs of arousal when answering these questions.

In addition, people who tell the truth may be anxious when answering questions, and therefore exhibit increased arousal.

This means that physiological changes are not necessarily a reliable marker of deception.

As a result, polygraph tests cannot be used as evidence.

They cannot be used as evidence in criminal court, nor as a basis for recalling offenders to prison.

Dr.  Sohom Das (pictured) is a forensic psychiatrist from London who also creates YouTube content on his channel A Psych for Sore Minds

Dr. Sohom Das (pictured) is a forensic psychiatrist from London who also creates YouTube content on his channel A Psych for Sore Minds

However, the results of pollography tests may be used by civil courts at the judge’s discretion

However, lie detector tests are sometimes used by law enforcement officers.

Dr. Das explains this in his video, saying, “They have been used to convince the perpetrator that they are completely accurate.

‘So they pressure the perpetrator to confess so that the perpetrator thinks he has to tell the truth and admits to the crime.

Dr. Sohom Das can be found at Tweet, InstagramAnd TikTokas well as YouTube.

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