“High-reactive introverts sweat more; low-reactive extroverts sweat less. According to some of the scientists I spoke to, this is where our notion of being socially “cool” comes from; the lower-reactive you are, the cooler your skin, the cooler you are. Lie detectors (polygraphs) are partially skin conductance tests. They operate on the theory that lying causes anxiety, which triggers the skin to perspire imperceptibly.”