Assessment, Statistics, and Research

AI image of a person taking a Polygraph test   Researchers have long investigated the validity and reliability of polygraph tests as tools for detecting deception. These tests work by measuring physiological indicators—such as blood pressure, respiration, and skin conductivity—that are thought to correlate with the emotional arousal often associated with lying. However, a substantial body of research has revealed that these responses are not uniquely linked to deception; they can also be triggered by stress, anxiety, or other emotional states not related to dishonesty (National Research Council, 2003). In controlled laboratory settings, polygraph tests have sometimes demonstrated moderate levels of accuracy, suggesting that under ideal circumstances they might differentiate between truth-telling and lying to some degree better than chance. Nonetheless, when these tests are applied in real-world or forensic settings, their accuracy tends to diminish markedly. Factors such as th...