Use of Polygraphs by Employers – a word of caution

Use of Polygraphs by Employers – a word of caution

Business, Human Resources, Legislation

Employers, particularly those that are in high risk industries such as the security sector, often use polygraphs or the “lie detector test” to ascertain an employee’s truthfulness.  Many businesses have incorporated the necessary permissions to utilise the test as a standard part of their employment contract and an obligatory polygraph test is performed as common practice during the on-boarding process. In this category of use as a support tool to combat crime in the workplace, the polygraph can play a significant part in decreasing business risk and discouraging misconduct as well as curbing incidences of economic crime.

A polygraph test can best be described as a tool in the “truthfulness” toolbox that the employer has access to.  In South Africa there is no legislation that governs the use of the test.  The Constitution upholds a person’s right to not be compelled to take the test unless they consent to it.

Prior to a test being performed:

An employee must consent in writing to the test and must also be informed of the following:

  • The examination is voluntary.
  • Questions to be used in the polygraph must be discussed prior to the test.
  • The employee may request an interpreter should it be necessary.
  • The person undergoing the test has the right to have another person present during the test. That person may not interfere with the test at all.
  • No abuse of the circumstances is permitted.
  • No discrimination is allowed.
  • No threats or bullying is allowed.

An employer is permitted to use a polygraph to investigate a specific incident.

  • The employee being investigated must have had access to property where the incident occurred.
  • There is a reasonable suspicion that the employee was actually involved.
  • There has been an impact to the employer’s business in terms of loss or injury.
  • The employer is seeking to establish honesty where this would be relevant to the business incl. establishing fraudulent behaviour in the Company.
  • The employer is verifying abuse of alcohol or other substances whilst an employee is on duty.

The polygraph test is inadmissible in court or at CCMA as evidence of guilt, the reason being that the test is not viewed as having the capacity to verify the falsity of a statement. The machine can only detect physiological changes to a person’s blood pressure, heart rate and perspiration response. Whilst voice stress analysis can also be used and this can be a significant indicator that someone is deceitful, there may very well be other reasons that certain stresses are recorded.

An example of this would be a polygraph test where this was conducted on an employee relating to the theft of money in an office. The question asked was “did you steal the money?” The answer was “no” and deception was indicated due to the recorded physiological changes to the person taking the test.  On investigation into this particular case it was found that the employee had left the office without permission and the theft had occurred in their absence; the stress noted on the polygraph was due to the fear of being found out that they had in fact left the office early without permission. This was subsequently discovered whilst checking CCTV footage.

South African courts and CCMA have accepted that a polygraph cannot prove guilt; it can merely reflect that deception is indicated.  If an employer fails to adhere to the rules relating to polygraphs this may well prejudice the case of an employer to prove guilt of an employee and if the employer subsequently acts on that information and institutes disciplinary processes or dismisses them, they could lose their case unless they have a decent raft of other evidence in support of the polygraph results.

The right to fair labour practices is built into South African labour law and included in that is the right to respect and dignity. In addition everyone has the right to privacy and freedom which includes the right to physical security.

Unauthorised use of a polygraph test would flout those rules and could potentially land an employer in hot water as was recently demonstrated in the CCMA case of a supermarket guard who was dismissed for failing a voice stress analysis test with his employer, (Mahlangi vs Corporate Investigating & Veracity Assessment (Pty) Ltd).

In the employment contract there was a pledge stating that it was an inherent requirement of the conditions of employment that the employee had to pass the test successfully. Following incidents of theft at the supermarket, tests were conducted on a number of guards; the employee failed the test and was dismissed.  This was in breach of the Labour Relations Act and the Constitution and was unlawful; the arbitrator stated that the guard should instead have been given a hearing and any other corroborating evidence the employer had should have been presented at that time.  The reliance solely on the testing system was considered unreliable.

The Commissioner found that the test alone could not justify termination of employment as a polygraph test or voice stress analysis test was inadmissible as guilt.  This would mean the guard had been dismissed on a suspicion alone and this was both procedurally and substantively unfair. Compounding this case, the employer had tried to engage the employee in a mutual termination contract after the fact.  The employee had continually declared his innocence.

The Commissioner awarded the employee a full year’s salary as recompense.