Whereas the physiology of the arousal response is to optimize fight or flight, the physiology of dissociation is to help us rest, replenish, survive injury, and tolerate pain. Where arousal increases heart rate, dissociation decreases it. Where arousal sends blood to the muscles, dissociation keeps blood in the trunk, to minimize blood loss in case of injury. Arousal releases adrenaline; dissociation releases the body’s own pain killers, enkephalins and endorphins.
