Lie detector's past and present life-can it really detect a person lying?

"If I'm guilty and I want to beat that machine, it's not a very difficult thing," said Sharon Stone, a psychopathic character in the "instinct". "90 years into the birth, the polygraph has been controversial-can it really detect a person lying?"

The multi-channel physiology recorder, which we often call a polygraph, was born in Berkeley, California, in 1921. Berkeley had a very famous sheriff, called August Vollmer, who presided over police reform and was a nationally renowned advocate of police specialization.

In fact, he wants to use the technology to make the police more law-abiding, to avoid the recurrence of the assault on the suspect. John Larson, a Berkeley police officer, invented the first polygraph, based on the theory of a psychologist William Moulton Marston that changes in blood pressure can reflect whether a person is lying. The psychologist later became a comic book writer and created the role of Wonder Woman, but this is a digression. Modern lie detectors measure more, including heart rate, blood pressure and respiration rate. Since its inception, however, the accuracy of the polygraph has been questioned.

In 1923, the Supreme Court ruled that scientific evidence, such as the evidence provided by a polygraph, could be used as conventional evidence only if it was "well received by the scientific community". Leonarde Keeler, who founded the Crime Testing Laboratory in 1930, is the first forensic laboratory in the United States, a year before the FBI. "Keeler is best at bluffing to make wearies plead guilty, or threaten to monitor them with a polygraph. "But 90 years later, the polygraph was not accepted by the scientific community, the legal profession or the political arena." Some people say it's like a 20th century of witchcraft.

In 2003, Gary Ridgway admitted he was the Green River killer who murdered 49 women in the Seattle area. Ridgway passed the polygraph test in 1987, but an innocent man failed. One idea is a psychopath or serial killer like Ridgway. Their level of anxiety is much lower than that of normal people, but there is no uniform conclusion on this aspect of psychological research.

George Maschke, the former US intelligence chief, said that devices such as polygraph were not scientifically based because he was invented by the interrogators, not by scientists. "Using any polygraph conclusion is dangerous and irresponsible. Lie detector is not scientific and not advanced, it is just interrogation means. May be able to help with sin, but it's not reliable. Lie detectors can be easily deceived, you may not be a spy or a pervert, as long as you know the answer to the quiz question, and then bite the finger or in the head to solve the equation or something can cheat the polygraph. ”

But does the new technology tell if a person is lying? Professor Geraint Rees, UCL, is not so optimistic that such devices will not appear in the short term. "We cannot say that a particular part of the brain is particularly active, indicating that this person is lying because each part of the brain has a variety of functions." ”

All right. Finally, take a look at the video and relax.