Second Draft
The lie detector is not accurate to use in the court as the evidence.
Have you ever told a lie? Or, have you ever noticed other people's lying? I think most people have the experience in both questions. But it is hard to distinguish lie and truth by oneself. We can just guess it based on our subjective judgment. And here is a device that can distinguish the lie, a lie detector!
The goal of a lie detector is to measure the truth from deception when giving answers to some questions. Nowadays the lie detector is widely used. It is used in the police investigation and in the court as the evidence. In addition, we need to do a lie detector test to attain a job, because certain government jobs like the FBI or CIA require the lie detector tests.
Common idea about the lie detector is that it is really accurate and reliable because it's based on the numeric data. But I think it is not accurate, so I argue that the lie detector's result for the evidence in the court is not proper. For these reasons, my argument is 'The lie detector is not accurate to use in the court as the evidence.'
Everyone knows distinguishing lie is not easy. We are not sure of it, Here is the device that named 'lie detector', as I said above in the introduction. You can find the meaning and the goal of the lie detector instantly as soon as you hear it.
In the court, the evidence plays the important role in making judgment. Also it can turn the final judgement. But If the lie detector is used in the court as the evidence like nowadays, we have to worry about the misjudgment of the lie detector. It is evindent that some innocent people can be damaged by it.
There is new information. Do you know that there are two types of the lie detector? Maybe no. There are polygraph and FRMI.
Polygraphs are devices that monitor a person's physiological reactions. A polygraph is used to monitor changes in the body. When a person is questioned about a certain event or incident, his or her phtsiological reactions such as heart rate, blood pressure, respiratory rate and perspiration(sweatiness), which are different from normal levels, can be measured.
Likewise, FMRI(Functional Magnetic Resonance Imaging) can distinguish the lie as the polygraph. However, there is the difference.
FMRI has several ways to detect. First, BOLD(blood oxygenation level dependent) sognal is used. This BOLD signal is the method for measureing the oxygen amount in the blood of brain. Second one is 'cognitive subtraction'. This process compares the picture of the brain that telling lie and telling truth.
Both Polygraph and the FMRI are the ways to distinguish the lie. However, polygraph record the physiological reactions, while the FMRI records the oxygen amount in the blood of brain.
First, FMRI of 'cognitive subtraction' is just relative. Most people think that vitalized parts of the brain are rekated to the liebased on the result of the FMRI. However, according to the study, there are some parts that are vitalized in FMRI but have no relative with lie. So, it means there are some vitalized parts that are not related with the lie. Therefore, some parts of the brain can be vitalized just to keep the balance in the brain. However, we can't know the reason for it. So we can only say that the FMRI of cognitive subtraction is just relative and not accurate.
Second, there are two limits in both polygraph and the FMRI. We can't remember all the thing exactly. There can have false memories. If so, why the false memory is formed? According to this research, social pressure has an effect on the recollection of people. And we can be encouraged not to think about whether our memories are real or not. Put simply, people are not able to distinguish true memory from false memory in some ways. Even, it is not accuracy to judge whether the true memory is really true.
Lastly, environment can be an obstacle to measure the lie(both of polygraph and the FMRI). A recent study found that interruption movement like moving the finger is let the credibility decrease about 33 percent. So the result of the lie detector is not accurate. The result can change according to the location of test or the mentak state of the experimenter.
I also find the information about change the standard to accept evidence in the court. In 1923, there was a boy named 'Frye' who was prosecuted due to the robbery and murder. In the trial, the court rejected the evidence of the lie detector because of the lack of accuracy. This precedent has been called 'Frye Rule' after his trial. This rule became the standard of the acceptance the evidence for over 50 years. However, the principle of the 'Dovert' was created in 1993 and after that, the lie detector's result started to be accepted in the court as the evidence. Dovert principle is the principle which decide whether the evidence is appropriate to be used as the evidence before accepting the evidence. It has 4 conditions to accept the evidence. And since then, the acceptance rate of the lie detector has been on the increase. According to the statistics, 19 states in the United States of America(USA) accepted the results of the lie detectors as evidence in the court from 1993 to 2003. I don't think this tendency is desirable. And I believe three limits and one precedent can support my argument. If I say again, my view is that the result, obtained from the lie detector caanot be used in the court as the evidence.
Some people can argue that the lie detector is accurate because it distinguishes lie based on the accurate figure. They seem to believe that the figure is more accurate than a person's guessing. They can also argue that there is no reason to reject for an innocent person to reject to receive lie detector test. They may think the lie detector is a useful instrumentsin the court because it just can be used for reference to the judgment. However, these arguments are not logical and rational. There are counter-reasons for these arguments as follows:
First, according to the research that I found above, there are information that tell the lie detector's record is just relative. So, even the record from the figure or the statistics, it is not accurate.
Second, there are many reasons to reject lie detector tests. I will pick out one example as evidence, we can be too nervous when we are suspected, although guiltless. And we may well worry about the misjudgment of the lie detector. The lie detector makes us nervous.
Lastly, if the lie detector is used just for reference, it can also have a significant effect on the judgment. It will make the judge and a member of the jury to be biased. In addition, it can be wrongfully used.
Do you know the Buzz's the most notorious episode in the history of the technology? Buzz is the man who was damaged from the lie detector's inaccuracy. Buzz was charged with murder, but he is innocent. So the police suggest to do the lie detector test, and of course, Buzz accept the suggestion because he didn't commit. However, the lie detector said that he is lying about his innocent. Although he didn't commit, the lie detector determine the truth as the lie. So he have to spent some years in the prison despite he is innocent. How unfair he is! Who will reward Buzz's time in the prison? Through this example, we can know the lie detector's inaccuracy. And if we use the lie detector as the evidence in the court, many examples like Buzz's will occur.
Also the result of the lie detector is relative and people can have many false memories, even though they don't recognize their wrong perception.In addition, the condition can be interrupt distinguishing lie. For these reasons, I strongly argue that the lie detector is not accurate to be the evidence in the court.
