Why did Pinocchio’s nose grow whenever he lied? Was there a lie detector inside of it?
This story is not entirely groundless. Dr. Alan Hirsch, researcher of the Smell and Taste Treatment Research Foundation in Chicago, found out that when a person lies, his or her nose actually grows a little as it secretes the chemical, catecholamines, which enlarges the nose’s blood vessels temporarily. Due to the inflation of blood vessels, nerve tissue at the end of the nose become irritated, and the liar comes to rub or touch his or her nose unconsciously. This is called the “Pinocchio Effect.”
In fact, when a person lies, it is not only his or her nose that responds. In anxiety and fear that the truth would leak out, the liar’s autonomic nervous system changes; his or her blood pressure goes up, the mouth becomes dry, his or her face turns red, or breaks out into a cold sweat. Like this, the liar’s body shows symptoms immediately.
However, the body doesn’t show physiological responses to a lie all the time. This happens only when a person tells a white lie to please another person. As he or she does not intend to harm or deceive someone, one does not need to feel anxious. In actuality, if you want to please others, wouldn’t it be more effective to be sincere, rather than to tell a white lie?