If our autonomic nervous system feels that a situation is unsafe, our response can shift down one phylum, from social engagement to the level of reptiles with a strong spinal sympathetic chain response, and we might fight to overcome the threat, or flee to avoid it. If the situation is so extreme that fighting or fleeing is not enough, we may shift down even further and shut down or collapse into a dorsal vagal state of withdrawal, dissociation, and shutdown.
