Field Guide · Glossary
Fight or flight
Body languageThe automatic physiological response to a perceived threat, which prepares an animal either to escape it or to confront it.
How it works
It is a reflexive state rather than a decision, driven by the sympathetic nervous system, and it changes what a dog is physically capable of: heart rate rises, attention narrows, and access to trained behavior drops away. Which of the two directions a dog takes depends heavily on whether escape is available. A dog on a leash frequently cannot take the flight option, which is one reason leashed dogs bark and lunge at things they would simply walk away from off-leash. Freezing is commonly included as a third response.
What it looks like
A dog meets an off-leash dog in a narrow alley with no room to pass. Unable to move away, they bark and lunge. The same dog, meeting the same dog in an open field, turns and trots in the opposite direction.
Commonly confused with
- Flooded
- Fight or flight is the acute response to a threat, and it resolves when the threat does. Flooding describes being held in that state with no escape until responding stops, which is a different and more damaging situation.
Related terms
Where this comes up