The reliability of polygraph tests depends on the examinee’s physical, mental, and emotional states.
For instance, individuals with severe psychological disorders may be deemed incompetent to take a lie detector test due to their distorted sense of awareness. The same is true for people reeling from the aftershocks of traumatic events.
But while polygraphs are traditionally administered to healthy individuals, the tests may safely be conducted on persons with disability (PWDs) too. All it takes is to make specific adjustments before polygraphing PWDs.
Here’s a detailed guide on how lie detector tests may be adapted for different disabilities.
Polygraph Guidelines for Different Disabilities
1. Pain
Polygraphs measure the degree of arousal of certain physiological responses controlled by the autonomic nervous system (ANS). Those include breathing, heart rate, and skin conductance.
But since the ANS is also involved in pain signaling, excruciating aches can impact an examinee’s reactions to lie detector test questions.
If someone is visibly in pain due to a recent injury or surgical operation, ensure they receive proper pain medication before having them take a lie detector test. However, only drugs that don’t impair the normal thought process should be prescribed.
Besides, gently attach electrodermal sensors to less sore hands. This is particularly recommended if one of the arms is severely burned or scalded.
2. Physical Disability
Physical disabilities can be presented in varied ways. It’s best to understand and examine an examinee’s specific condition before adapting proper interventions.
People with mobility impairments may need to take polygraph tests in locations near their residences. Alternatively, make arrangements for their safe travel to the pre-agreed testing location.
If the examinee is unable to walk, help them get into the examination chair.
In the case of hand amputations, the EDA sensors can be attached elsewhere – it is not an option to forego that recording. These sensors would need to be attached to alternative locations, such as the examinee’s legs.
3. Visual Impairment
The biggest challenge to polygraphing visually impaired individuals is getting them to read and sign consent forms.
Note that a polygraph examinee must willfully submit to the tests in writing, or the results will automatically be deemed unreliable.
Since consent forms can be quite voluminous, you could ask the examinee to invite their attorney, or another trusted third party to help with the document interpretation. However, ensure the individual appends their signature.
4. Hearing Impairment
Polygraphing individuals with hearing impairments will most certainly require a sign language interpreter.
You can help the examinee find a certified signing interpreter. However, ensure they approve of the person before going ahead with the polygraph questioning.
Note that incorporating an interpreter can extend the testing duration considerably. However, stick to the industry benchmarks of 1.5 – 2.5 hours.
5. Speech Impairment
One fundamental principle when designing polygraph questions is that each query must attract a direct “Yes” or “No” answer. Yes responses are typically expected from victims and their witnesses, while suspects usually reply No to most questions.
This principle makes lie detector tests easily adaptable to persons with speech impairment.
During the in-test phase, an examinee can answer ‘Yes’ by nodding their head or ‘No’ with a head shake. For pre-test and post-tests that often require narrative replies, the examinee can write down their responses.
6. Anxiety Disorders
Polygraphing individuals with anxiety disorders can be exceedingly challenging. It’s only worse, considering that lie detector tests generate considerable anxiety levels, and intense anxiety can arouse the autonomic nervous system.
Fortunately, this is where the expertise of a qualified examiner comes in.
7. Cognitive Impairments
Polygraphs rely heavily on normal cognitive functioning. Key aspects to consider here include attention span and situational awareness.
If a polygraph examinee isn’t cognitively aware of their surroundings, they may not understand the full implications of taking a lie detector test. That makes it exceedingly challenging to conduct credible examinations.
Individuals with cognitive conditions like attention deficit hyperactivity disorder (ADHD) need extensive evaluation before subjecting them to lie detector tests.
Polygraphing such examinees would also require a multi-disciplinary approach involving licensed polygraphers, mental health therapists, and behavioral experts. Besides, each test should include several irrelevant questions to diffuse anxieties and maintain the examinee’s focus.
8. Memory Impairments
Memory impairment is another critical aspect to consider before administering a lie detector test. While typically less symptomatic than other cognitive disabilities, the condition can be remarkably challenging to navigate during polygraph tests.
Note that an examinee must have photographic recollection to respond appropriately to polygraph questions. Therefore, impaired memory will most certainly impact the process and outcome.
An examiner must establish the cause and extent of memory loss before recommending a person for a polygraph test.
Impairments triggered by neurodegenerative conditions (such as Alzheimer’s disease) and traumatic brain injuries (TBIs) tend to be the most severe. In such cases, it’s best to have the examinee undergo complete therapy before scheduling a polygraph test.
Implementing Proper Adjustments When Polygraphing PWDs
People with disabilities can safely undergo polygraph testing. However, certain safeguards are necessary to guarantee the accuracy of such lie detector tests.
Before scheduling a polygraph exam, consider the examinee’s physical and mental state. Severe symptoms must be alleviated before subjecting the individual to a lie detector test.
Besides, remember to uphold basic ethical standards while polygraphing persons with disabilities. Each examinee deserves respectful treatment, regardless of their physical or mental condition.
Keep the questioning objective, focusing on the case under investigation rather than the examinee’s limitations.
