Lie detection - voodoo or science?

pcl paper Lie detection voodoo or science?

by Geoff Trickey

published in the Personnel Manger’s Yearbook Online The dictionary definition of a lie, “an intentionally false statement” seems clear enough, until you look into it a little closer.

Consider exaggerations of advertising, the distortions of mis-selling, spin in the world of politics, the subtle deceptions of poker playing, the exaggerations of research claims, flattery and all those little white lies we tell. Through tooth fairies and Father Christmas we routinely lie, even to our children! If you Google ‘dishonesty’ you get 3,550,000 hits, so this must be a significant preoccupation.

Only the saints are untainted. I would go so far as to say that no one (other than these saints) could honestly claim that they had never knowingly told a lie. The principle of ‘deceive to survive’ is even recognised in evolution, which has developed an extraordinary range of techniques for protection by deception. This starts with intricate and ingenious camouflage and extends into animal behaviour. Squirrels deceive by pretending to bury nuts, taking attention away from their true hiding places. Chimps will play similar mind games to preserve their own stash of goodies. It seems deception is endemic across all forms of life.

At the human level, dishonesty pollutes communication and this is the age of communication - we are flooded with it! The internet and emails provide a bountiful new breeding ground for new kinds of dishonesty, fraud and deception; stalking, grooming, identity theft and no doubt many other horrors that have yet to come to public consciousness. Consider too the elaborate and costly structures we have erected to deal with it; the criminal justice system, the security industry and the legal professions.

It’s no wonder that all this concerns us as individuals, as well as concerning recruiters and employers. Costs of dishonesty at work are immense and can be enough to derail a business. In surveys conducted by Deloitte & Touche between 2003 and 2005, 20% to 33% of respondents believed that they had to act unethically and to ”bend the rules” to succeed in their careers. A staggering 40% said they would act unethically if directed by their boss, and would lie to cover a mistake. Not that I’m at all convinced that asking people if they lie is the most canny way of checking this out!

So the picture, it seems, is that we have all lied at some time and we tolerate many shades of dishonesty in our private and public lives. We even have a soft spot for the charm of old rogues like Arthur Daley, Mr Punch, Fagin, Bill Clinton, Alfie, Robin Hood or Fletcher in Porridge. At the same time, we worry about being deceived.

But of course, the other thing we know on this subject is that our ability to detect lies is sadly lacking. For confirmation that our ability to sum others up is hopelessly inadequate, buy any tabloid. You will find an endless supply of stories reflecting the deceit, betrayal, deception and dishonesty of humanity and the inability of victims to see what’s coming. This truth is bought home to us by all those studies that demonstrate the ineffectiveness of the bog standard job selection interview.

Copyright © 2008 Psychological Consultancy Ltd www.psychological-consultancy.com

pcl paper Lie detection voodoo or science?

by Geoff Trickey

So we certainly need help, but is any at hand?

‘Lie detectors’ were once very prominent in the US. At a time when science seemed to have all the answers, it was viewed as the appliance of science to the detection of deception. These instruments, actually called polygraphs, do not detect lies as their nickname suggests. They actually measure a person’s heart rate, blood pressure, respiratory rate and electro-dermal activity (sweatiness, in this case of the fingers). The examiner interprets the fluctuations in these measures that occur under questioning, and makes a judgement whether or not these indicate that the person is being deceptive. The important point is that results are open to interpretation, and trained experts do not always agree.

The US courts do not typically permit polygraph evidence unless both parties in the dispute agree to it. This ambivalence stems from the questionable validity of polygraph results, which may be anything from 70% to 90% accurate, depending if you listen to the detractors or the advocates. Either way, the chances of incorrectly being labelled a liar range from 10% to 30% according to these estimates. A further difficulty in using the polygraph for employee selection is that there is no specific event or suspicion around which questioning can focus. The investigation has to be more general and more speculative.

Integrity tests overcome some, but not all, of these difficulties. They can be divided into those that use personality assessment techniques to give an index of reliability, and those that address honesty issues head on. Some widely used personality questionnaires, Hogan’s HPI for example, include a scale that is, in effect, an integrity measure. High scorers on the HPI Reliability Scale would be described as “good organisational citizens; people who are generally honest, dependable, and responsive to supervision.” Such people keep their impulses under control, keep out of trouble and tend to maintain constructive relationships. The Attitudes to Honesty scale, on the other hand, is typical of the second approach, where the focus on honesty is direct rather than inferred. High scores are associated with a concern for truthfulness and honesty and lower scores with a more casual or expedient attitude towards these issues.

These tests are used where there is a particular emphasis on security. This may be where employees have access to very high value items – such a precious stones – or where high staff turnover and a culture of casual employment mean that no one gets the chance to get to know anyone well.

There is a particular sensitivity about integrity testing that arises from the idea that low scorers would be labeled as dishonest.

Given that any selection process will result in some false positives (where those selected prove unsuitable) and some false negatives (where those rejected would have been suitable), categorising individuals in this way is clearly unacceptable.

In reality low scorers on integrity tests, as a group, are just more varied than high scorers with respect to honesty. There will therefore be a greater probability of picking the wrong person when you select from this group.

An integrity questionnaire should be viewed as providing reassurance concerning an applicant’s attitudes and values,

Copyright © 2008 Psychological Consultancy Ltd www.psychological-consultancy.com

pcl paper Lie detection voodoo or science?

by Geoff Trickey

not as putting people in discrete boxes. Integrity tests can contribute important additional dimensions to pre-employment screening, but should be considered alongside other opportunities for job candidates to convey their abilities, their personalities and their integrity. Validity research suggests that, in general, integrity tests are able to identify the prospective employees that are less likely to be problematic. But like all other attempts to gauge dishonesty, it is a matter of probability rather than certainty.

A free sample Attitude To Honesty report can be downloaded from the PCL website http://www.psychological-consultancy.com/ath-1.htm

Copyright Š 2008 Psychological Consultancy Ltd www.psychological-consultancy.com