With his dying breath, Fred Ery identified Floyd “Buzz” Fay as his murderer.
“Buzz did it,” he whispered to his wife, even though the assailant had covered his face and fled quickly from the scene.
Ery had been shot as he worked late in his small general store, but managed to give Buzz’s address shortly before he died on the operating table. Only a few hours later, the police had Buzz’s house in Ohio surrounded.
When Buzz was charged with aggravated murder, he did not seem particularly perturbed.
“I kept thinking, they’ll find the right person, they’ll get this straightened out, they’ll let me go tomorrow,” he told the Calgary Herald. “I wasn’t even going to hire a lawyer.”
The county prosecutors offered Buzz a deal: They would drop all charges if he agreed to take a polygraph — a lie detector test — to prove his innocence. Convinced the whole episode was one big mistake, Buzz readily agreed. He took two tests, but both suggested he was lying about his innocence. This, along with circumstantial evidence, sealed his 1979 conviction and he spent two-and-a-half years in prison for a murder he did not commit.
During his time in prison, Buzz studied the polygraph. He sent his results to a number of experts, but received wildly different interpretations. Determined to show the test was fallible, he developed a training exercise to help people fool the lie detector and after just 15 minutes of instruction, 23 out of 27 inmates beat the polygraph. Buzz was eventually exonerated, helped by the testimony of the real killer’s mother, and his case has become one of the most notorious episodes in the history of the technology.
The name “lie detector” is misleading in many ways. First, the polygraph does not actually detect lies, but, instead, measures arousal. It is based on the idea that we will be a little more stressed, with fleeting changes in blood pressure, sweat gland activation and respiration, when answering questions with lies compared to giving truthful responses. The majority of tests involve comparing responses to control questions that the interviewee will respond truthfully to (“Are you sitting in a chair?”) with responses to investigation-relevant questions (“Did you handle the money?”).
The “lie detection” part comes from an interpretation of the differences in arousal between these types of answers. However, physiological differences may arise for many reasons, not just from intentional deception — I may become more stressed if I worry that I will not be believed, or if the question concerns something that is naturally arousing — perhaps even just a question that contains highly emotional words.
Because there is no pattern of arousal that is unique to deception, the decision to classify a set of responses as untruthful is inevitably a leap from the shaky ground of ambiguous data into the fog of inference. As a result, techniques to “beat” a polygraph are simple and effective. The simplest strategy seems to be to increase arousal during the control questions, rather than trying to reduce arousal during deception, to eliminate any difference.
Second, if I want to know that someone is telling the truth or not, I want to make sure that the technology produces as few false positives and false negatives as possible. For example, just as I can correctly punish all criminals by throwing everyone in jail (innocents, or false positives, be damned), I could correctly “detect” 100 percent of lies just by classifying every answer as a falsehood.
Accuracy, however, requires a balance. Reviews of the scientific evidence by the National Research Council in the US and the British Psychological Society in the UK have indicated that the polygraph has an accuracy of about 85 percent when evaluating genuinely guilty people. Unfortunately, the accuracy is probably nearer to 50 percent (with results here varying greatly across studies) when attempting to do the same with genuinely innocent people.
However, despite the inherent unreliability of lie detectors, they have recently seen a rebirth. Even though the British have always been reticent about the technology, police in Hertfordshire, north of London, recently announced a trial using polygraphs to monitor convicted sex offenders. This is undoubtedly because recent studies have shown that offenders will actually produce more risk-relevant information during interviews when wired up to a polygraph than during a standard police interview.
Yet this is unlikely to be due to the technology itself; years of research have shown people are more truthful when wired up to a convincing, but fake machine — the so-called “bogus pipeline to the truth” effect.
A 2007 study by psychologist Theresa Gannon and colleagues at the University of Kent, England, tested exactly this effect with sex offenders. Child molesters who were attached to a bogus polygraph admitted higher levels of offense-facilitating thoughts and beliefs than those who were just given a standard interview.
So if it leads to more information, should not the police be using it? For those who want to base offender monitoring on a technique that relies on ignorance for its validity, it is unfortunate that none of these details is secret, as they have been discussed openly in scientific and lay forums for years.
Any form of risk management that relies on an offender not knowing about Google is inherently flawed, but perhaps more importantly, we have a responsibility to ensure that the police are not basing public safety on methods that are so easily fooled.
Vaughan Bell is senior research fellow at the Institute of Psychiatry at King’s College London.
US President Donald Trump and Chinese President Xi Jinping (習近平) were born under the sign of Gemini. Geminis are known for their intelligence, creativity, adaptability and flexibility. It is unlikely, then, that the trade conflict between the US and China would escalate into a catastrophic collision. It is more probable that both sides would seek a way to de-escalate, paving the way for a Trump-Xi summit that allows the global economy some breathing room. Practically speaking, China and the US have vulnerabilities, and a prolonged trade war would be damaging for both. In the US, the electoral system means that public opinion
They did it again. For the whole world to see: an image of a Taiwan flag crushed by an industrial press, and the horrifying warning that “it’s closer than you think.” All with the seal of authenticity that only a reputable international media outlet can give. The Economist turned what looks like a pastiche of a poster for a grim horror movie into a truth everyone can digest, accept, and use to support exactly the opinion China wants you to have: It is over and done, Taiwan is doomed. Four years after inaccurately naming Taiwan the most dangerous place on
In their recent op-ed “Trump Should Rein In Taiwan” in Foreign Policy magazine, Christopher Chivvis and Stephen Wertheim argued that the US should pressure President William Lai (賴清德) to “tone it down” to de-escalate tensions in the Taiwan Strait — as if Taiwan’s words are more of a threat to peace than Beijing’s actions. It is an old argument dressed up in new concern: that Washington must rein in Taipei to avoid war. However, this narrative gets it backward. Taiwan is not the problem; China is. Calls for a so-called “grand bargain” with Beijing — where the US pressures Taiwan into concessions
The term “assassin’s mace” originates from Chinese folklore, describing a concealed weapon used by a weaker hero to defeat a stronger adversary with an unexpected strike. In more general military parlance, the concept refers to an asymmetric capability that targets a critical vulnerability of an adversary. China has found its modern equivalent of the assassin’s mace with its high-altitude electromagnetic pulse (HEMP) weapons, which are nuclear warheads detonated at a high altitude, emitting intense electromagnetic radiation capable of disabling and destroying electronics. An assassin’s mace weapon possesses two essential characteristics: strategic surprise and the ability to neutralize a core dependency.
RSS