Born Liars (10 page)

The polygraph is not pure hokum. A racing pulse and an increased heart rate can indicate guilt, and when combined with a skilled operator the machine can achieve high success rates (although the necessity of a skilled operator rather defeats the purpose). But Ames is right; much of the polygraph's effectiveness is itself based on a lie – the lie of its own infallibility. Its key flaw is that there is no utterly reliable physiological sign of lying. All the symptoms it measures can have other causes, including the sheer nervousness that many honest people feel when confronted by such a test.

The lie detector never caught on in Europe, and in the country of its birth it failed to meet the standard of general scientific acceptability for evidence used in court. But the machine did become a staple of the policeman's interrogation armoury.
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Police cared little for the science – they just knew that presenting suspects with this magical device was a great way of extracting a confession (in a scene from HBO's
The Wire
, based on real-life police practices in the 1980s, officers are shown extracting confessions by putting a suspect's hand on a photocopy machine filled with paper printed with the word LIE). The US military and intelligence services used polygraphs extensively over the years to interrogate suspected spies or terrorists, confirm the loyalty of allies, check the veracity of tip-offs and – as with Ames – check on the reliability of its own employees. But in 2001 a Pentagon report to Congress concluded that ‘national security is too important to be left to such a blunt instrument'. A 2003 report by America's National Academy of Sciences concluded that the polygraph performed ‘well above chance, though well below perfection'. It is still used by the federal government, though rarely in law enforcement or by the military.

The polygraph insinuated itself into many areas of twentieth-century American life. In the 1930s and 1940s it was introduced, with Keeler's help, to banks, factories and government departments eager to check on the honesty and reliability of their employees. It became a political symbol, since it met, or appeared to meet, a demand for certainty about individual integrity that grew more strident as the country moved on to a Cold War footing. In the trial of Alger Hiss, Richard Nixon called for the suspected spy Whittaker Chambers to take the test even though, as Nixon remarked to a friend, ‘I don't know anything about polygraphs and I don't know how accurate they are but I know they scare the hell out of people.' Senator Joe McCarthy issued polygraph challenges to the 205 Americans he accused of being communists in his speech of February 1950. The polygraph also became a pop cultural icon, featured in movies, TV series and magazines. It was the man whose insight led to the first polygraph prototype who best understood the machine's cultural potency.

Born in 1893 in Boston, William Moulton Marston was a chubby-faced, ebullient, irrepressibly optimistic man. At Harvard he worked in the prestigious ‘emotion laboratory' of Hugo Münsterberg, where Marston and his fellow students experimented with an apparatus that registered responses to emotions such as horror and tenderness through the graphical tracing of pulse rates. One student volunteer was Gertrude Stein, who later wrote of the experience in the third person: ‘Strange fancies begin to crowd upon her, she feels that the silent pen is writing on and on forever.' Marston was the only one of the three men with a claim to the invention of the polygraph never to have worked in law enforcement. Instead, his research into deception launched a colourful career that saw him become America's first pop psychologist.

During the 1930s Marston often appeared in magazines such as
Esquire
and
Family Circle
, carrying out his ‘deception test' on willing young females, and featured as a guest on TV game shows. He was hired by Universal Studios to measure the emotional impact of their movies, and lent his expertise and name to advertising agencies, who liked using his test as an ersatz form of market research. An ad for Gillette shows Marston analysing a polygraph tracing while a man is shaving. The copy reads:

Strapped to Lie Detectors, the same scientific instruments used by G-Men and police officers throughout the country, hundreds of men take part in an astounding series of tests that blast false claims and reveal the naked truth about razor blades. These men, shaving under the piercing eye of Dr. William Moulton Marston, eminent psychologist and originator of the famous Lie Detector test, come from all walks of life, represent all types of beards and every kind of shaving problem. Knowing that the Lie Detector tells all . . . these men shave one side of the face with a Gillette Blade, the other side with substitute brands.

Marston was fascinated by the new forms of mass entertainment, and believed that with the right guidance they could help solve America's deep-rooted emotional problems, which he put down to women not yet being the dominant gender. Women, argued Marston, were superior to men. Men had a stronger sexual appetite and a will to dominate, while women preferred to cultivate ‘the love response'. But this seeming submission would eventually enable women to take command of the species. In a hundred years, he predicted, ‘the country will see the beginning of a sort of Amazonian matriarchy.' He viewed the lie detector as a tool to fine-tune the emotional content of culture and, by doing so, to teach men and women what they really wanted.

At home, Marston lived in a harmonious
ménage a trois
with his wife Elizabeth and his mistress – and research assistant – Olive Byrne. He had two sons with each woman. Elizabeth, who worked as a lawyer, was the breadwinner. Olive looked after the kids during the day and helped with Marston's experiments. Their sons later recalled the arrangement happily. An evening's entertainment might include hooking up a guest to the lie detector. After Marston's death, Olive and Elizabeth continued to live together, and did so for the rest of their lives.

Of the three men who invented the lie detector, Marston was the only one who didn't suffer for it. What may be his greatest invention was not in the fields of psychology or law enforcement, but popular culture. Marston had been invited onto the board of DC Comics, who were eager to appease critics worried about the emotional impact of comic strips on kids. He asked his new colleagues why there wasn't a female superhero, a counterpart to Superman, and was informed, wearily, that such characters never worked. Marston responded that this was because there had never been a character who combined strength with femininity. Challenged to come up with an answer himself, Marston created Wonder Woman, who wielded a golden lasso that made all who are encircled by it tell the truth.

The polygraph turned out to be rather more fallible than the lasso of truth. Today, brain-scanning techniques promise to succeed where it failed. These new technologies appear to offer the tantalising possibility of getting beyond the external signs of lying to the lie itself, written in the brain's neuronal activity.

The two main brain-scanning technologies used for lie detection are known as EEG (electroencephalography) and fMRI (functional magnetic resonance imaging). EEG measures electrical activity in the brain caused by the firing of neurons, via multiple electrodes placed on the scalp of the subject. During a typical EEG-based lie detection test, the subject – or suspect – is shown a series of images and words that may or may not relate to the ‘crime' of which he or she is accused. According to Peter Rosenfeld of Northwestern University, who has done the most to develop this technique, when somebody recognises a stimulus, they involuntarily emit a particular type of brain wave (the P300) which the administrator of the test can detect. In theory, no matter how much the suspect denies recognising the name of a fellow bank robber or the face of his victim, their P300 will blurt out the truth. This kind of technique is sometimes called the ‘guilty knowledge' test.

When breathless articles about the end of lying are published, however, they invariably focus on fMRI, just as eighty years ago they trumpeted the polygraph. Functional MRI, invented in the early 1990s, has primarily been used as a research tool to better understand how the brain does its work. The technique produces images of the brain in action, which in an image-obsessed age is bound to attract attention. Not that fMRI isn't worthy of it. Unlike the polygraph, it is a genuinely revolutionary technology, which has transformed the field of neuroscience.

To take an fMRI scan, a person must be lying down inside a machine that is, basically, a very large, very powerful magnet. Once in the scanner, they can be asked to perform a variety of tasks, such as listening to music, answering questions, or pressing buttons in response to images shown on a screen above them. As they do so, the technology detects which areas of the brain are more active than others. When neurons fire they consume more oxygen, which leads to an increase in the flow of oxygenated blood to the active region; this causes distortions in the local magnetic field which can be measured by the machine. These changes can then be translated into images, using highly involved – and sometimes controversial – statistical methods. The process is nuanced and complex, but the end result is attractively simple: pictures of the brain with areas of relatively high neural activity mapped in brightly coloured blobs. The theory behind the use of fMRI for lie detection is that the extra cognitive effort demanded by lying can be traced in neural activity, so when a person is asked a series of questions, and answers one of them deceptively, the lie – or rather the moment when they lied – can be picked out in red and blue.

As America battles terrorism and fights wars, the Pentagon's Defense Academy for Credibility Assessment has been a generous patron of research into deception-detecting technologies. There is much talk about the potential for civilian applications, too. It's been suggested that schools will use scanners to check for plagiarism, that airports will ask people to have their brains screened along with their baggage, that employers will have a new way of checking out job applicants, and that immigration agencies will check the validity of a visitor's thoughts as well as their passport. At least two American companies, Cephos and No Lie MRI, already sell fMRI scans to individuals who want to prove their innocence, or to vet potential life partners, and they are lobbying hard to get fMRI deception tests accepted as evidence in court. Law professors and ethicists are beginning to consider the tricky questions these new methods pose, such as whether the results of brain scans should stand as evidence, and, if so, whether they should be classified as something akin to a DNA sample, or as testimony.

EEG and fMRI lie-detection tests have produced some encouraging results under laboratory conditions. Ruben Gur, a professor at the University of Pennsylvania who researches into fMRI lie detection, showed me the results of his scans, flicking between the ‘true' and ‘false' answers to demonstrate the stark differences in brain activation shown up by the machine. It is likely to be a long while before such tests will be more reliable than human judgement, however. Neither EEG nor fMRI have been field-tested in the real world, where a thousand complications intrude. For example, the guilty knowledge test may not work if the suspect was too high on drugs or drink at the time of the crime to recall very much about it. The investigator has to know the concealed information he is looking for, and there are only certain circumstances in which recognition is enough to establish guilt. Another limitation of such tests is that they require full co-operation: even once the subject is inside an fMRI machine, if he moves his head during the test then the data is useless. (This at least postpones the murky ethical question of whether a suspect should ever have his mind read against his will.) Furthermore, nobody is sure whether fMRI can reliably distinguish between a lie and a true memory that is effortful or painful to recall.

And what if the suspect doesn't know whether or not he's telling the truth?

On 8 July 1997, a US Navy officer called Bill Bosko returned to his apartment in Norfolk, Virginia, after a week at sea, to find his wife murdered in their bedroom. She had been raped and repeatedly stabbed. Michelle Moore-Bosko was nineteen years old. The pair had only recently married, after Michelle had run away from her parents' home to wed in secret.

Soon after arriving at the crime scene the police arrested Bosko's naval colleague Danial Williams, who lived across the hall. After eight hours of interrogation, Williams confessed to the rape and murder of Michelle, describing to investigators how he had beaten her with his fist and a shoe before raping her. Williams' confession sparked a series of arrests as police became convinced that he had acted in concert with several other men, including his roommate, Joseph Dick, and two other sailors, Derek Tice and Eric Wilson. The other three men also confessed under interrogation, and later pleaded guilty at trial in a deal to escape the death penalty. Dick publicly apologised to the victim's family. ‘I know I shouldn't have done it,' he said, just before the judge gave him a double life sentence. ‘I have got no idea what went through my mind that night – and my soul.'

The case was not straightforward, however. Puzzlingly, investigators never found DNA or fingerprints connecting any of the suspects to the crime. Then, while the men were awaiting trial, it emerged that a convicted rapist called Omar Ballard had written to a friend claiming that he had killed Michelle. When police took a sample of his DNA it proved to be a match with that found at the scene of the murder. (Ballard eventually pleaded guilty in court and said that he had acted alone.) Despite this new information, Norfolk police and prosecutors continued to pursue their case against Tice, Dick, Wilson and Williams. After the men were found guilty, suspicions grew that a major miscarriage of justice had occurred, and in 2005 the Innocence Project, a non-profit group that works to clear people who have been wrongfully convicted, took up the cause of the ‘Norfolk Four'. It assembled an impressive collection of legal and forensic experts who believed the men to be innocent.