Lie detectors, also known as polygraphs, operate by measuring physiological responses that are believed to change when a person is lying. These responses include:
1. Heart Rate: Increased heart rate can indicate stress or anxiety.
2. Blood Pressure: Like heart rate, elevated blood pressure may signal stress.
3. Respiration: Changes in breathing patterns can suggest discomfort or deception.
4. Skin Conductivity: Also called galvanic skin response, this measures sweat gland activity, which can increase during lying.
Working Principle:
When a person lies, it’s assumed they might feel nervous or anxious, leading to noticeable changes in these physiological responses.
The polygraph records these changes on a graph as the subject answers a series of questions.
Limitations and Accuracy:
Not Foolproof: The accuracy of lie detectors is debated. Factors like nervousness, medications, or even training can affect results.
Not a Mind Reader: It measures physical responses, not the act of lying directly.
Legal and Ethical Considerations:
Courtroom Use: Many legal systems limit or prohibit the use of polygraph evidence due to questions about reliability.
Ethical Concerns: The potential for false positives or negatives raises ethical issues regarding their use in sensitive situations.
SRIRAM’s:
It’s crucial for civil services aspirants to understand the workings and controversies surrounding lie detectors, as they intersect with legal, ethical, and psychological domains, relevant in various aspects of governance and law enforcement.