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Myths surround the use of polygraph machines. Lie detector photo from Shutterstock.

Lie detectors and anti-doping – who’s kidding who?

Please, sit down. Try not to sweat. Just relax. Now, answer honestly: could lie detectors succeed where current anti-doping measures in sport are failing?

If you answered “yes” you are not alone. There are worrying signs some anti-doping agencies, such as UK Anti-Doping, are advocating that polygraph machines be used in their investigations.

The words “clutching” and “straws” come to mind. The anti-doping movement has recently come under intense pressure with revelations at the Australian senate inquiry that, despite summer Olympics sports spending nearly A$1.2 billion on testing every four years, only 0.89% of anti-doping testing has uncovered a “meaningful” violation.

In addition, according to Athlete Ombudsman for the US Olympic Committee John Ruger at the Tackling Doping in Sport summit in the UK earlier this month, between 40-60% of positive test doping results were inadvertent (non-deliberate) cases.

Wikimedia Commons

In spite of the huge investment of resources, there has been only a limited beneficial return to society as a whole. The current Australian policy narrative is to pursue a criminal detection and law enforcement framework instead of a more imaginative approach focussing on athlete health.

Rather than devoting resources to the education of athletes and towards evidence-based preventative measures, the current direction of sport seems to be headed towards ever more coercive measures to convict athletes.

Which brings us back to lie detectors.

Polygraphs and science

Lie detector tests have become a popular cultural icon synonymous with television crime shows. Unfortunately, as temptingly simple as the idea may be, the notion that a person’s genuineness can be assessed by monitoring psychophysiological changes in the body, and the “truth” therefore determined, is misguided.

Most psychologists in the scientific community, including the American Psychological Association, agree that there is little evidence polygraph tests can accurately detect lies.

The lie detector typically consists of a physiological recorder that assesses various indicators of physiological responses to emotions: heart rate, blood pressure, respiration rate, and skin conductivity (sweating).

The myth – and simplistic view – is that a person’s natural fear of being caught out when telling a lie will result in an increased physiological response when answering the questions with a lie as opposed to when answering truthfully.

American inventor Leonarde Keeler (1903-1949) testing his lie detector in 1937. Agence de presse Meurisse‏ via Wikimedia Commons

Several questioning techniques are commonly used in polygraph tests. The most common in criminal incident investigations is the Control Question Test (CQT).

This test compares the physiological responses to pertinent questions (“Did you inject yourself with anabolic steroids during the Olympics?”), with those of “control” questions that concern similar past transgressions that are usually more generic in nature (“Have you ever used oral supplements in your sporting career?”).

The theory is that an individual who is truthful fears control questions more than the pertinent question under inquiry. Greater physiological responses to pertinent questions than to control questions suggest a lie.

Unfortunately, there is no credible scientific evidence to show any pattern of physiological response is unique to telling the truth or lying. Both anxious but honest and non-anxious but dishonest individuals exist.

A machine used to detect physiological response is unable to differentiate between the two. Moreover, there is evidence to indicate countermeasure strategies used to “beat” polygraph examinations are often effective. These may include the use of simple physical movements (such as increasing one’s respiratory rate or by self-inflicting of pain); psychological interventions to manipulate beliefs about the test (such as hypnosis); and the use of pharmacological agents to alter physiological responses.

Hard to believe

Perhaps owing to the lack of scientific credibility for polygraph tests, research has begun using functional brain MRI (fMRI) as a new physiological measure. This method is used to identify brain regions associated with deceptive answers versus truthful answers.


There is still limited information on the interpretation of experimental fMRI findings and real world context of lie detection and it remains to be seen how this technology measures up in terms of reliability and validity.

At present, fMRI is limited only to the research context because of the requirement for scientific robustness and also due to financial cost. Nevertheless, both the traditional physiological measures and fMRI used in polygraph tests remain questionable and susceptible to the test giver’s subjective interpretation and the test taker’s objective manipulation.

Polygraphs and the law

The most credible scientific evidence rejects polygraph testing as a valid measure for truthfulness. Despite this, the tests are still used in the legal forum, often by individuals seeking to convince others of their innocence.

Alberto Contador. kwc

For example, in the case of Spanish cyclist Alberto Contador in 2012, a leading professor called by the defendant suggested to the Court of Arbitration for Sport (CAS) panel that polygraphs have an accuracy of 95%.

In the UK, polygraph evidence is not used in courts, but it has begun to impact upon other legal procedures. Sex offenders can now be assessed and monitored upon release based in part on lie detector tests.

Polygraph evidence is used in criminal proceedings in some US states although it is often said that the role of the jury in deciding the truth should not be usurped by scientific devices and the like.

Polygraphs and sport

The use of polygraph or lie detector evidence in sports law cases has been much debated. Given that evidence beyond adverse analytical findings is being used more frequently to prove doping violations pursuant to the World Anti-Doping Agency (WADA) Code, there are calls for the use of such evidence, both to prove cases against and to exonerate athletes accused of doping.

In light of the limited value of laboratory testing in detecting anti-doping violations (inadvertent or not), one wonders if the use of a polygraph is merely an attempt (either by the athlete or anti-doping agencies) to be able to influence the outcome of a verdict using a quasi-scientific technique as a façade.

Steve Waugh. Eva Rinaldi Celebrity and Live Music Photographer

In cricket, in a bid to fight corruption, ex Australian captain Steve Waugh led calls for the use of lie detectors.

Waugh “convincingly” passed a test to demonstrate that he had never been involved in match fixing.

Meanwhile Lance Armstrong’s lawyer’s statement in 2012 that the cyclist would be willing to take such a test to prove his innocence suggests he was massively confident of successfully defeating it – given it transpired he was ultimately guilty.

The American cyclist Tyler Hamilton also admitted in his 2012 book The Secret Race to being able to beat the lie detector machine during a less truthful period of his life.

The position of CAS with regard to the admissibility of this type of evidence has shifted. In 2008, four-time America’s Cup winner Simon Daubney sought to rely upon a successful polygraph test to prove his innocence of knowingly taking cocaine.

CAS ruled that such evidence was inadmissible under Swiss law and accordingly any statement made by Daubney was admissible only as a personal declaration. The expert scientific evidence was not admissible.

Subsequently in the case of Contador, he successfully argued that, pursuant to WADC Article 3.2 – “facts relating to an anti-doping violation may be established by any reliable means” – which had not been in force at the time of Daubney, polygraph evidence was admissible. The admissibility was not challenged by the other parties.

CAS ruled that the evidence added “some force” to Contador’s “declarations of innocence, but do not, by nature, trump other elements of the evidence”.

With the recent push for wider use of polygraphs in anti-doping proceedings, this legal position might change.

To be honest …

The polygraph won’t cure sport’s doping ills. Further research may advance its usefulness, but the real emphasis for change should focus on athlete education and prevention.

Current anti-doping strategy is hampered by a lack of resources in a constant fight against a resourceful drug industry. A shift in emphasis is required towards a more creative inclusive process.

Better evidence-based policy is needed to combat the issue, but not at the expense of innocent athletes. The use of polygraphs is not the answer.

This article was co-written by Philip Gibbs, a sports barrister at KCH Garden Square.

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