Fight-or-flight Response - Psychology of The Stress Response

Psychology of The Stress Response

A typical example of the stress response is a grazing zebra. If the zebra sees a lion closing in for the kill, the stress response is activated. The escape requires intense muscular effort, supported by all of the body’s systems. The sympathetic nervous system’s activation provides for these needs. A similar example involving fight is of a cat about to be attacked by a dog. The cat shows accelerated heartbeat, piloerection (hair standing on end, normally for conservation of heat), and pupil dilation, all signs of sympathetic arousal. Note that the zebra and cat still maintain homeostasis in all states.

Though Cannon, who first proposed the idea of fight-or-flight, provided considerable evidence of these responses in various animals, it subsequently became apparent that his theory of response was too simplistic. Animals respond to threats in many complex ways. Rats, for instance, try to escape when threatened, but will fight when cornered. Some animals stand perfectly still so that predators will not see them. Many animals freeze or play dead when touched in the hope that the predator will lose interest.

Others have more exotic self-protection methods. Some species of fish change color swiftly, to camouflage themselves. These responses are triggered by the sympathetic nervous system, but, in order to fit the model of fight or flight, the idea of flight must be broadened to include escaping capture either in a physical or sensory way. Thus, flight can be disappearing to another location or just disappearing in place. And often both fight and flight are combined in a given situation.

The fight or flight actions also have polarity – the individual can either fight or flee against something that is threatening, such as a hungry lion, or fight for or fly towards something that is needed, such as the safety of the shore from a raging river.

A threat from another animal does not always result in immediate fight or flight. There may be a period of heightened awareness, during which each animal interprets behavioral signals from the other. Signs such as paling, piloerection, immobility, sounds, and body language communicate the status and intentions of each animal. There may be a sort of negotiation, after which fight or flight may ensue, but which might also result in playing, mating, or nothing at all. An example of this is kittens playing: each kitten shows the signs of sympathetic arousal, but they never inflict real damage.