08/11/2025
Polygraph testing: How young is too young?
https://liedetector.ie/uncategorized/polygraph-testing-too-young-to-tell/
The Ethics and Limits of Polygraph Testing Young People
The polygraph, commonly known as the “lie detector,” has long been used to measure physiological signs of deception. While widely used with adults, its use on young people raises some ethical and developmental considerations. For instance, the polygraph exam requires the child to have a certain level of abstract concept comprehension and language skills to complete the lie detector successfully.
The Age Question - The American Polygraph Association (APA), the leading polygraph organisation in the world generally considers individuals 12 years or older suitable for polygraph testing. However, this is not a hard rule — suitability depends heavily on jurisdiction, individual maturity, and comprehension. Polygraph testing can only work effectively if the person tested can understand abstract questions about truth, consequences, and morality.
At Lie Detector Ireland we consider 12 years of age to be too young and generally only test adults. For anyone considering booking a polygraph test for their child there are a number of factors they should consider first.
Considerations for Age and Polygraphs -
Maturity
Regardless of how mature a parent may believe their child to be; a child’s brain and cognitive functions are still developing, which can make it difficult for them to understand and respond to questions truthfully during the test. The examiner may use terminology the young person does not understand or words or phrases that are new or uncomfortable. Their understanding of reality verses fantasy may not be fully established, which can impair their ability to respond reliably to polygraph questions.
Younger children in particular may lack the abstract reasoning needed to process complex questions. Their developing brains are still learning to link actions with outcomes — a key part of accurate testing.
Understanding and Comprehension:
Polygraph questions often involve abstract ideas and nuanced language. The examination process requires the young person being tested to fully understand the abstract concepts the examiner will introduce during the pre-test part of the process. Young people may not fully understand the complex and precise language used in polygraph questions, leading to misinterpretation that can affect physiological responses.
Insight and Morality:
To achieve valid results, the subject must clearly understand the difference between right and wrong and differentiate between truth and lies — and the moral or legal weight behind both. Younger children may confuse imagination with reality or struggle to separate a lie from a misunderstanding, reducing the validity of results.
They may struggle to grasp the difference between telling the truth and lying, and the consequences of their actions.
Children’s memories can be less reliable than adults and are more susceptible to manipulation, which can lead to unreliable test results.
Difficult remaining Still:
To obtain reliable test data then it is imperative that the person being tested sits still for several minutes at a time. Young people can struggle with this which can lead to inaccurate results or the examiner not being able to issue a result.
Legal and Ethical Standards:
Whilst there are no age restriction in Ireland, if a person under 18 is being test, written consent should be obtained from their parental or legal guardian. In addition to this the young person themselves must also be a willing participant. Coercion, such as threats of punishment, subverts the process and renders the results unreliable and ethically questionable.
Psychological Harm:
The polygraph process can be stressful and anxiety-inducing. For a child, this can cause significant emotional distress or psychological harm, particularly if they are innocent but fear being wrongly accused.
When it comes to polygraph testing for young people, the search for truth must be balanced with understanding. Until a child can grasp abstract ideas of right and wrong, the test’s readings may reflect fear, not falsehood.
Consider all of these facts before deciding if polygraph testing your child is the right decision.