Joyce Guee

“As young children, seen in the laboratory for the first time, their heartbeat rates are generally higher and under stress show less change. (Heart rate can’t change much if it is already high.) Also when under stress, their pupils dilate sooner, and their vocal cords are more tense, making their voice change to a higher pitch. (Many HSPs are relieved to know why their voice can become so strange sounding when they are aroused.) The body fluids (blood, urine, saliva) of sensitive children show indications of high levels of norepinephrine present in their brains, especially after the children are exposed to various forms of stress in the laboratory. Norepinephrine is associated with arousal; in fact, it is the brain’s version of adrenaline. Sensitive children’s body fluids also contain more cortisol, both when under stress and when at home. Cortisol is the hormone present when one is in a more or less constant state of arousal or wariness. Remember cortisol; it comes up again.”
― Elaine N. Aron, The Highly Sensitive Person