Final answer:
The polygraph detects physiological arousal rather than lies, which can indicate a strong emotional response, but is not necessarily definitive of dishonesty or guilt.
Step-by-step explanation:
The polygraph does not detect lies, it detects arousal.
While a polygraph, often referred to as a lie detector test, is commonly used to assess whether a person is being truthful, it does not directly measure dishonesty or guilt. Instead, it measures physiological responses such as heart rate, respiration rate, and sweating, which can indicate strong emotional responses or physiological arousal. This is based on the assumption that dishonesty would typically result in noticeable physiological responses due to emotional arousal when lying. However, these physiological responses are not exclusive to lying and can be triggered by a variety of emotions or external factors, casting doubt on the accuracy and validity of polygraphs. Experts debate the efficacy of polygraphs, as they can be influenced by factors other than lies, making it difficult to reliably determine whether someone is lying based solely on physiological arousal. Furthermore, individuals with psychopathic tendencies may not exhibit typical arousal patterns, which is an issue highlighted in research such as the work by Hare (1965) and Fung et al. (2005).