Since ancient times, a curious phenomenon has been described in many animal species: people have been able to induce state of prolonged immobility in the animal by using various methods. Over time, the phenomenon has gone by several names, from the most evocative animal hypnosis to the more scientific tonic immobility. For some years now, investigations have been examining analogies between this phenomenon and conditions occurring in humans, such as the immobility that accompanies severe trauma and sexual violence, wartime situations, catalepsy, cataplexy, catatonia and the immobility experienced in panic attacks. This book reviews the literature on these tonic immobility (TI) phenomena in animals and the comparative psychological research that has investigated how this model can contribute to our understanding of aspects of human behavior.