Can a lie detector detect lies?

People who don't lie think it's mysterious, and people who lie think it's terrible. This is a magical lie detector. In the face of rising crimes, good people always expect to catch all criminals with the help of scientific panacea. Supporters of polygraph technology are persuading people that polygraph is a panacea. So, can you see through a lie? Will the popularization of lie detection in China really help the lie detection activity? The word "polygraph" comes from "polygraph"; The original text of "lie detector" is literally translated as "multi-recorder", which is an instrument for recording various physiological reactions. In criminal investigation, it can be used as an auxiliary interrogation to understand the psychological state of the interrogated suspect and judge whether a criminal case is involved. Because the real criminal suspect will deny the case and lie at this time, it is commonly known as "polygraph". Accurately speaking, "lie detection" is not to measure the "lie" itself, but to measure the changes of physiological parameters caused by psychological stimulation. Therefore, "polygraph" should be scientifically and accurately called "multi-parameter psychological test" and "polygraph" should be called "multi-parameter psychological tester". The first person who tried to "lie-detect" with scientific instruments was Hugh Lomb. 1895, he developed a "hydraulic pulse recorder" to judge whether the suspect is related to the case by recording the changes of pulse and blood pressure, and successfully detected several cases. In the past hundred years, the polygraph has been updated for several generations and made great progress. As a general technology, polygraph technology has been widely used in national defense, justice, insurance, business and even enterprise recruitment in more than 50 countries around the world. According to statistics, from 1990 to 199 1, Romania detected 1833 cases with the accuracy rate of 95%. Statistics from Japan show that the accuracy of polygraph is 86%. In the United States, polygraph technology was first widely used in the police, security departments and private detectives, and then gradually extended to the routine polygraph of federal government employees and military insiders. In the 1970s, it became more socialized, and was also used by institutions and enterprises to recruit employees, regularly evaluate employees and solve internal theft cases. The association has also set up a professional polygraph company and a polygraph office. This has also caused some "unjust, false and wrong cases" and aroused strong protests from AFL (trade unions) in the United States. 1988 stipulates that it is forbidden to use polygraph in private companies, except for companies that have signed contracts with the state to undertake important national defense secrets. In the United States, on the one hand, the legal profession recognizes the scientific nature of polygraph and allows the results of polygraph to be submitted to the court as evidence; On the other hand, its application is strictly restricted, and it is stipulated that only professionals with higher education and special training are qualified to take the polygraph. Now, the polygraph has become a common equipment in foreign police organs. The United States, Canada, Japan, Turkey, South Korea, Israel, Russia, Poland and other countries use polygraph technology more. In addition, 3050 countries are studying "polygraph" technology. Romania's "polygraph" has been approved by the judicial department as a legal means to provide evidence. "Lie detection" has been included in the routine procedure of criminal investigation by foreign police organs, and there is a section on "Lie detection" in the published Handbook of Court Psychology, Handbook of Criminal and Civil Investigation and Handbook of Criminal Evidence Investigation. Today, 35 states in the United States allow polygraph results to be used as auxiliary evidence in court, but the results must strictly meet the requirements of American evidence law. Regarding the forensic evidence function of "polygraph" results, China used to think that "polygraph is idealistic" and totally denied it. It wasn't until the relevant personnel of the Ministry of Public Security visited Japan in 1980s that they realized that "polygraph is scientifically based" and decided to carry out polygraph work in China. 198 1 year, China introduced the American-made Mark-II polygraph. Up to 1985, cases have been handled in Beijing, Shenyang, Nanchang and other places 16, and the accuracy rate is about 90%, which shows the obvious effect of "polygraph" technology in assisting pre-trial work. 199 1 year, the "polygraph research group" composed of the Institute of Science and Technology Information of the Ministry of Public Security and the Institute of Automation of China Academy of Sciences developed the "PG- 1 psychological tester", which was put into trial in June of the same year. Based on this, the public security organs in Liaoning Province have solved several long-term unsolved cases with only suspects and lack of physical evidence. The accuracy of excluding the innocent is 1 0,000%, and the accuracy of identifying the innocent is 98%. Even the American authorities were surprised and said, "We haven't done it yet!" Since then, the domestic polygraph has become famous. Subsequently, the Ministry of Public Security listed the project as a key project during the Eighth Five-Year Plan. During the ninth five-year plan period, it was also included in the national key scientific and technological projects. At present, PG-7 polygraph has been developed, and the test parameters have been increased to include skin resistance, blood pressure, pulse and respiration. At present, more than 100 units in China have used polygraph. The polygraph has been used in public security and judicial departments at all levels in China for several years, and has successfully helped to solve a large number of difficult cases. Someone asked: Can the polygraph be introduced into China's justice, and the psychological polygraph results of criminal suspects can be directly used as evidence? In this view, experts in the judicial field believe that although the polygraph is so magical, from the current legislation in China, the conclusion of polygraph can not be directly used as evidence in court. The seven kinds of legal evidence stipulated in Article 42 of the Criminal Procedure Law of People's Republic of China (PRC) do not include the conclusion of polygraph. The reason is that the reliability (accuracy) of polygraph technology and its conclusion is not perfect. At present, in our country, because the introduction, development, research and application of polygraph technology are still in the initial stage of development, as a high-tech, the research and application in judicial work is still a new field that few people set foot in. The polygraph results cannot be directly used as evidence. We should take a realistic attitude towards polygraph technology, and we should not be absolute. We should not only see its scientific nature and positive role in the trial, but also realize the limitations of this technology, so that this high-tech can be continuously improved and developed in the trial work. Not long ago, People's Court Newspaper published a signed article, proposing not to popularize polygraph. The article said that although the lie detector has its scientific basis, because people's thoughts are very complicated, the authenticity of their psychological activities and words cannot be completely consistent with the map of scientific data. Secondly, for people with mental illness, congenital heart disease, sinus arrhythmia or special training, the polygraph may also be biased and misjudged. Moreover, from the perspective of judicial practice, there are different opinions on whether the test results of polygraph have evidential force. In the United States, there is such a situation that even if it is agreed by the parties in a specific court, the test results of polygraph cannot be used as evidence. It can be seen that even in the United States, where the polygraph is first used, the evidential validity of the test results is not always recognized. In fact, it is difficult to prove the existence of specific facts even if it is determined that the parties are lying without evidence to prove the existence or establishment of criminal facts or some civil and administrative legal relationship. At this time, the test results can only show that what the parties said is untrue, but what the real content is needs other evidence to prove that the polygraph can't measure the facts. Although lie detection cannot be the only basis for solving crimes in China, it has become an important means to solve crimes. It is reported that from 199 1 up to now, nearly 2,000 cases have been solved by lie detectors in China, and relevant departments in Shandong, Anhui, Zhejiang, Hubei, Yunnan, Inner Mongolia, Heilongjiang and other provinces and regions have been equipped with lie detectors. Experts made it clear: "As a commodity, polygraph should be gradually extended to China's judicial organs." At present, there are many potential clients of polygraph technology in China. Experts suggest that the following two departments can consider introducing polygraph technology: First, procuratorial organs, in the process of investigating anti-corruption cases, the suspects faced by investigators are generally high-quality and relatively hidden officials. Most of the criminal circumstances of such cases occur in the case of "one-on-one", and it is difficult to obtain evidence and break through. It is more advantageous to use polygraph technology to deal with such people. Second, insurance companies, there have been many insurance fraud cases. Once the polygraph technology is introduced, if the insurance company suspects that the applicant's motives are impure, it can entrust a polygraph institution to conduct a polygraph test on the applicant before handling the insurance formalities. Those with impure motives may be denied insurance. In addition, in the claims stage, if the insurance company suspects that someone is deliberately cheating, it can also take a polygraph. A polygraph is not everything. Of course, polygraph, like any means of investigation including technical means, has its special functions and limitations. Lie detection can never replace investigation and interrogation. It is not illegal to take a polygraph with the consent of the candidates, perform the necessary procedures, and take a polygraph in strict accordance with the requirements of the polygraph procedure, and it can receive the due results. But the abuse of polygraph will lead to bad consequences. Finding out the case mainly depends on painstaking investigation, investigation and interrogation, and polygraph technology can only be used as an auxiliary investigation means. We should seek truth from facts and correctly understand the function of polygraph technology, that is, we should not completely deny it, nor expect too much from it and exaggerate its function. Recently, the media has blown the lie detector to the gods. People are misled by the lie detector of media myth: with it, no matter how cunning criminals are, they can't escape legal sanctions, and even the most difficult cases will be "solved at once"; With it, the judicial and discipline inspection departments can easily crack major cases and clean up social evils just around the corner. In fact, the polygraph is not omnipotent, and the evidence it "produces" is the same as other scientific evidence, and it is impossible to be 100% correct. The object of polygraph work is a living and thoughtful person, and the instrument detects the psychological change parameters of the examinee. Therefore, the psychological status of the subjects is directly related to the test results.