Lie detector tests have been used as a way to detect the truth in many circumstances, from criminal investigations to employment screening. While lie detector tests appear to be helpful for determining the truthfulness of someone’s answers, they are not always accurate.
Therefore, it’s important for people considering taking such a test to arm themselves with all the information to decide whether it is suitable for them.
How do lie detectors work?
Lie detectors, also known as polygraphs, measure physiological responses to questions to detect whether someone is telling the truth. When a person takes a lie detector test, sensors record their breathing rate, pulse (heart rate), blood pressure and perspiration. These measurements are then compared to the person’s baseline responses when answering simple questions. If there is an increase in any of these areas when answering more difficult questions, it can indicate that the person is lying.
In addition to measuring physical responses, some polygraph tests also use psychological techniques such as asking the same question multiple times or using different phrasing for the same question to detect inconsistencies in answers.
Many consider lie detector tests to be highly accurate when administered by a trained professional in an appropriate setting. However, they can also be unreliable if the person administering the test is inexperienced or the environment is not conducive to accurate results. Other factors that may skew results include:
- Certain medications, such as beta-blockers or anti-depressants
- Physical conditions like high blood pressure, respiratory problems or neurological conditions
- Mental health conditions like anxiety disorders or personality disorders
In general, it is best to understand your legal rights before taking a lie detector test.