Cognitive Load Theory

Lying is mentally expensive. A liar must suppress the truth, construct a plausible alternative, monitor your reaction, and keep consistency with previous statements. This cognitive overload leaks through the body in micro-delays, hesitations, and unnatural stillness.

Paul Ekman identified seven universal micro-expressions that flash involuntarily: happiness, sadness, anger, fear, surprise, contempt, and disgust. A glance combined with self-touching and speech hesitation is a pattern worth investigating.