“Your muscles tensed up, your blood pressure rose, and your heart rate increased. Someone looking closely at your eyes while you tackled this problem would have seen your pupils dilate.” — Daniel Kahneman Copy Share Image
“Constriction alters a person’s breathing, muscle tone, and posture in order to promote efficiency and strength. Blood vessels in the skin, extremities, and internal organs constrict so that more blood is available to the muscles, which are tensed and prepared… — Peter A. Levine Copy Share Image
