A man hooked up to a polygraph machine. Chinese companies are beginning to offer lie detection services. Photo: CFP
We live in a world of lies. Every single day lies cloud investigations, politics, transactions and marriages. Everyone from astute politicians to shrewd business elites, insane murderers and changeable lovers are going about their business of deceit. There is a machine that can supposedly catch these dishonest denizens, though China is only just discovering its potential.
Over the last few years, several companies have gradually set up, claiming to offer polygraph services to the public.
A modern polygraph tracks changes in a person's physiology, including their blood pressure, pulse, respiratory rate and skin conductivity. In theory, this can deduce whether a person is telling the truth or lying.
These services are normally clandestine and publicity shy, the machines they use are still a sensitive topic; they are legally only allowed to be licensed by the authorities.
One employee from a Beijing-based company under the Chinese Academy Sciences which offers the service told the Global Times that: "polygraphs are offered for between 40,000 yuan ($6,350) and 200,000 yuan, but only organizations under the public security authorities can purchase the machines, as the usage of polygraphs is still quite a delicate issue."
Other companies offer polygraph services for varying fees. They normally advertise the test as a way to catch a cheating lover, or screen new employees. One Shandong-based polygraph-testing company was offering half-day tests for 3,000 yuan per person, and claimed they would travel to Beijing if expenses were paid. "The machine is exactly the same as the ones used by the police in criminal cases," said one employee surnamed Lü. "We organize a set of 50-60 questions according to the customer's requests," he added.
The polygraph was invented in the US in 1921 but was only legalized for use in China in 1991. Today, there are still die-hard followers who are attempting to get the device recognized as a valid forensic technique.
"Prior to the country's major economic reforms, psychology was considered something from a capitalist ideology and a pseudoscience that should not be encouraged," said Wu Boxin, a retired professor of criminal psychology from Chinese People's Public Security University (CPPSU).
The device is still used in some forensic investigations around the world, but a polygraph is not admissible evidence in European and Canadian courts, nor in many US states and is regarded by some as having little credibility. In China, it can be used by police only to help with investigations.
"Polygraph results would really help during investigations," protests Wu. "Any flaws in the results normally stem from poor examiners, whose key role is to design and ask questions during a test."
China's first criminal expert
Wu is dubbed China's first expert on the criminal mind. As a young man he developed a passion for the works of French political philosophical writer Jean-Jacques Roussea. He continued to study the mind when, as a student in the 1960s, he was sent to the countryside, where he observed prisoners undertaking reeducation through labor. He graduated from Northeast Normal University to become a professor at CPPSU.
Over more than a decade, he has been involved in more than 1,300 criminal investigations including unsolved murders, burglaries, and other outstanding cases.
In 2010, Wu used the polygraph on suspects in the murder of an elderly lady who was killed, sexually abused and burnt in a village in Northeast China. He is convinced the polygraph helped to identify the killer, and the police cited his work. This, he says, is a difference in China's use of the polygraph.
"The Americans often apply a polygraph after apprehending a suspect, while Chinese use the technology to get information from others about the criminal," he added. "The examiner's interpretation accounts for 70 percent of the results."
Polygraphs are not infallible, and can be tricked.
"The opinions of people on polygraph results are divided," said Wang Dawei, professor of criminology at CPPSU. "When a subject is suffering from depression or anxiety, the stress can drive them to overreact and produce a lie-reaction from the polygraph."
And it's not just medical conditions or anxiety that can trick the device. "The polygraph has been used very little by the police in the recent past," said Tian Jun a lawyer from Beijing based lawfirm Yixing. "If a criminal has strong self control, he can pass a polygraph no problem."
Despite detractors, and his own admissions that a bad examiner produces a bad result, Wu still believes that the tests are 98 percent accurate. But, that hasn't prevented scandals in the past.
In 1998 Du Peiwu from Yunnan province was sentenced to death for killing his wife. The results of polygraph was adopted by the police in Du's conviction. The real killer later confessed when brought up on other charges, and Du was released.
Future of truth
Wu suggests that there are only 100 people in the country that are trained and capable to use a polygraph accurately, and they have all been assigned to provincial or municipal governments.
As the man at the head of the only institution licensed to train them, Wu knows that there won't be much more recruits in the future, since they'd rather keep the polygraph on the down low as much as possible. That still doesn't seem to have affected all the companies offering marital lie detection, so perhaps China's love affair with the polygraph is just beginning.
Chinese you need:
Lie：撒谎 (sā huǎng)
Dishonest：不诚实的 (bù chéng shí de)
Polygraph：多种波动描计器 (duō zhǒng bō dòng miáo jì qì)
Clandestine：秘密的 (mì mì de)
Delicate：微妙的 (wēi miào de)
Legalize ：合法化 (hé fǎ huà)
Pseudoscience：伪科学 (wěi kē xué)
Design：设计 (shè jì)
Criminal：犯罪的 (fàn zuì de)
Reeducation：再教育 (zài jiào yù)
Suspect：嫌疑人 (xián yí rén)
Apprehend：逮捕 (dài bǔ)
Infallible：绝对可靠的 (jué duì kě kào de)
Self control：自控 (zì kòng)
Detection：侦查 (zhēn chá)