Polygraph outcomes aren’t always cast in stone. There are instances where retests are necessary, such as when examinees challenge the results or a policy requires periodic screening.
If you’re planning repeat polygraph exams, you may wonder if the process will yield consistent outcomes over time. Well, there’s no cut-and-dried answer.
While you may pass all polygraph exams despite how frequently they’re repeated, certain factors may have you fail the tests even if you’re truthful.
Read on as we examine the role of repeat lie detector tests in revealing consistency over time.
What Is A Repeat Lie Detector Test?
A repeat lie detector test is a polygraph exam conducted after an initial screening process. It can be a follow-up exam designed to validate previous findings, or rescheduled evaluations conducted after previous tests were cancelled.
Reasons for Repeat Polygraph Tests
1. DI and INC Results
A polygraph examinee challenging the outcome of a Deception Indicated (DI) outcome may request a retest. Similarly, examiners can recommend retests if the process yields Inconclusive (INC) results.
Whether a repeat test is due to a DI or INC outcome, it’s best to have the subsequent exam undertaken by another examiner.
2. Countermeasure Detection
Some examinees may deploy countermeasures in an attempt to beat a lie detector test. Fortunately, professional examiners are trained in effective countermeasure detection.
An examiner may pause and reschedule the test if they prove countermeasure usage.
3. Physiological Interferences
Lie detector tests should happen in a safe and comfortable environment. The room should be free from distractions, including glaring lights, loud noises, and too much décor.
If unforeseen distractions occur mid-test, it may be necessary to reschedule the procedure.
4. New Information
Before scoring a lie detector test, examiners should ask examinees to explain some of their responses.
Providing new, material information during post-test interviews may necessitate a follow-up exam or a complete retest.
5. Institutional Procedures
Certain institutions mandate ongoing lie detector tests, regardless of the outcome of previous exams.
For instance, convicted sexual offenders typically undergo Post-Conviction Sex Offender Testing (PCSOT) to assess if they pose a significant threat to society. Besides, national security agencies like the Federal Bureau of Investigations (FBI) polygraph their employees as part of their counter-surveillance efforts.
How Frequently To Schedule Repeat Polygraph Tests?
The frequency of repeat polygraph exams depends on the test type and the reasons for conducting subsequent evaluations.
According to the American Polygraph Association (APA), PCSOT exams are best administered every six months.
National security agencies may require full scope polygraph retests every five years. However, frequent re-examinations are often necessary to monitor countersurveillance or review clearance privileges.
For polygraph retests occasioned by cancelled exams, the re-examination can happen at the next available opportunity.
Dangers of Scheduling Retests Too Frequently
When you conduct lie detector tests too frequently, examinees may become habituated.
Habituation occurs when a subject’s physiological reactions diminish because they’ve had to reply to similar polygraph questions too often. The phenomenon reduces an individual’s ability to respond naturally to frequently repeated questions, making it challenging to conduct professional exams.
But merely spacing out lie detector tests isn’t enough. Examiners can enhance polygraph accuracy by;
- Preparing examinees adequately
- Framing the questions clearly and objectively
- Using APA-validated scoring methodologies
Dangers of Infrequent Polygraph Tests
While spacing out routine polygraph exams is critical, the tests shouldn’t be too far apart. Note that polygraphs rely on memory recall, particularly episodic memory.
Episodic memory is responsible for bringing past events into the present. When an examiner asks a specific question like “Did you stab Mr. Jeffrey last Tuesday,” the examinee must immediately remember the incident and understand their role in it.
However, studies have shown that episodic memories can fade over time. If polygraphing an individual on specific events like auto accidents or homicides, the initial test must be conducted as soon as possible, and any retests scheduled closer apart.
For ongoing security assessments, the retests can follow a more structured routine.
Repeat Tests and Polygraph Consistency
Taking multiple polygraph exams can provide conclusive results, eliminating the bias associated with single tests.
A convicted sex offender may pass a polygraph evaluation the first time but fail the subsequent test. Therefore, releasing such individuals purely based on the initial reports would be catastrophic.
Similarly, a new FBI employee may pass a polygraph exam during their first year in office but become a double agent three years later. That underscores the importance of repeat tests.
However, passing a polygraph exam consistently may not always imply honesty.
Memory-impaired examiners can lie without experiencing deception-linked physiological arousal. Similarly, a well-rehearsed lie can exert less cognitive load over time, while truthful individuals may show less consistency because they rely on genuine but fading episodic memory.
Working with a qualified examiner is the best way to ensure consistency with polygraph retests.
Repeat Polygraphs and the Prospect of Truth Degradation
Polygraph tests rely on memory recall. Therefore, their accuracy depends on how far back an incident occurred rather than how frequently the exams are administered.
Examiners must follow APA guidelines in determining the frequency of repeat polygraph exams. Conducting the tests too frequently can lead to habituation, while spacing them too far apart may cause inaccurate results due to poor recollection.
As noted, the testing type also determines the frequency of lie detector tests.
PCSOT exams should be administered biannually to ensure the parolee complies with their parole conditions. For routine assessments, such as countersurveillance tests, an annual or biennial frequency would be ideal.
