One thing is certain: Yelling at someone who is already out of control can only lead to further dysregulation. Just as your dog cowers if you shout and wags his tail when you speak in a high singsong, we humans respond to harsh voices with fear, anger, or shutdown and to playful tones by opening up and relaxing.
— Bessel Van der Kolk, The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma (New York: Penguin, 2014), 87–88.
