Group one of the National Congress on Judicial Reform preparatory committee passed a resolution that would prohibit performing polygraph tests — commonly known as lie detector tests — on the disadvantaged, in the hope of protecting the rights of disadvantaged victims and defendants in lawsuits.
However, defining “disadvantaged” is problematic. Another issue to consider is whether a polygraph test would be more or less effective depending on whether the subject belongs to a privileged or a disadvantaged group.
The premise for polygraph testing is that the truth or falsehood of one’s statement will trigger a specific, uncontrollable, physiological reaction in the subject that can be measured and then interpreted by an expert. These assumptions may appear scientific, but they have always been controversial.
The doubts about performing polygraph tests mainly focus on their objectiveness: Whether the examiner is an expert, whether the polygraph instrument meets standards, whether the environment where the test is performed is normal; all these factors will affect the results of a test, and in combination with the fact that physiological conditions differ between people, the question is how there could be a consistent benchmark for evaluation.
Other scientific tests, such as DNA tests, are not affected by such factors, and such tests can be reproduced by other experts using the same procedure, which means that their accuracy is extremely high.
In comparison, polygraph testing cannot rule out many of the variables, which means that it does not have the reproducibility required by science, and the accuracy of the process and the results cannot be examined — a fatal weakness of polygraph testing.
Although practical criminal justice in Taiwan does not rule out this method of evidence, it does require that the examiner has received expert training and is experienced, that the equipment is of good quality and operates normally and that the environment does not interfere.
In addition, polygraph tests require that the subject is in a normal physical mental state. In order to keep the respondent in this state, examiners must inform the subject of their right to refuse the test and the possible effects of polygraph testing, and they must verify that the subject’s physical and mental state is conducive to conducting a test.
That there are so many requirements reveals the concern that a lie detector test carried out under duress will violate the defendant’s right to a defense and that results are likely to be distorted.
Although judicial practice has such strict requirements around polygraph testing, in reality these requirements might not be met, because the environment is controlled by the interrogator and the subject is alone. Even if the subjects are innocent, it is doubtful whether they would be in their normal physical and mental state.
Furthermore, there is no institution to issue expert certificates to interrogators and no objective standard for procedures, which raises the question of how polygraph results should be validated.
Even worse, polygraph testing is often carried out because prosecutors think defendants are not telling the truth. This creates a risk that examiners might be prejudiced and makes it difficult to ensure that they are truly objective. Even if the defendant does not confess, these factors would make it hard not to fail the test, in effect turning it into a confession.
It often happens that even if the subject passes the polygraph test, the authorities reject the result and send the defendant to another institution for another test. This not only seriously violates the defendant’s right against self-incrimination, it also raises suspicions that defendants are given polygraph tests over and over again to frame them.
The validity of the polygraph test in criminal trials therefore has nothing to do with whether the subject belongs to an advantaged or disadvantaged group. However, it is necessary to comprehensively review whether this technology is a matter of pseudoscience disguised as science and whether it should be banned from the courtroom.
After all, the mindset that if a defendant does not confess, they will be subjected to a polygraph test — and if they do not pass the test, they are guilty — violates the presumption of innocence and is possibly a source of injustice.
Wu Ching-chin is chair of Aletheia University’s law department.
Translated by Lin Lee-kai
Donald Trump’s return to the White House has offered Taiwan a paradoxical mix of reassurance and risk. Trump’s visceral hostility toward China could reinforce deterrence in the Taiwan Strait. Yet his disdain for alliances and penchant for transactional bargaining threaten to erode what Taiwan needs most: a reliable US commitment. Taiwan’s security depends less on US power than on US reliability, but Trump is undermining the latter. Deterrence without credibility is a hollow shield. Trump’s China policy in his second term has oscillated wildly between confrontation and conciliation. One day, he threatens Beijing with “massive” tariffs and calls China America’s “greatest geopolitical
Ahead of US President Donald Trump and Chinese President Xi Jinping’s (習近平) meeting today on the sidelines of the APEC summit in South Korea, an op-ed published in Time magazine last week maliciously called President William Lai (賴清德) a “reckless leader,” stirring skepticism in Taiwan about the US and fueling unease over the Trump-Xi talks. In line with his frequent criticism of the democratically elected ruling Democratic Progressive Party — which has stood up to China’s hostile military maneuvers and rejected Beijing’s “one country, two systems” framework — Lyle Goldstein, Asia engagement director at the US think tank Defense Priorities, called
A large majority of Taiwanese favor strengthening national defense and oppose unification with China, according to the results of a survey by the Mainland Affairs Council (MAC). In the poll, 81.8 percent of respondents disagreed with Beijing’s claim that “there is only one China and Taiwan is part of China,” MAC Deputy Minister Liang Wen-chieh (梁文傑) told a news conference on Thursday last week, adding that about 75 percent supported the creation of a “T-Dome” air defense system. President William Lai (賴清德) referred to such a system in his Double Ten National Day address, saying it would integrate air defenses into a
The central bank has launched a redesign of the New Taiwan dollar banknotes, prompting questions from Chinese Nationalist Party (KMT) legislators — “Are we not promoting digital payments? Why spend NT$5 billion on a redesign?” Many assume that cash will disappear in the digital age, but they forget that it represents the ultimate trust in the system. Banknotes do not become obsolete, they do not crash, they cannot be frozen and they leave no record of transactions. They remain the cleanest means of exchange in a free society. In a fully digitized world, every purchase, donation and action leaves behind data.
RSS