Why does my dog react to some people and not to others, when there is no difference between them? The answer is trigger stacking.
When a dog reacts, whether he barks, bites or chases someone away it is because his brain can take no more triggers. A trigger is anything that starts the stress reaction in the dog’s body and mind.
A stress reaction is physical. It’s not something that a dog could control, even if he wanted to, it’s an innate survival response to a threat. Once long ago for both of our species, it was beneficial to us. As we have become physically safer the stress reaction has remained.
Why Stress is Physical
The name given to a sudden influx of stress is “acute”. It culminates in a rush of cortisol and a huge production of adrenaline. The dog cannot control it and yet it feels cripplingly intense.
Think back to a time when you have suddenly been terrified and your knees wobbled, you went lightheaded and lost complete control of your mind, a good example is a near miss if someone cuts you up whilst driving.
The physical stress reaction causes an ancient fight or flight response. The brain goes into fast forward reactive mode. Then if the trigger is removed the brain goes into reverse and the dog starts to calm down. If the trigger gets closer or more threatening in the dog’s mind* then the brain will fast forward at an alarming rate, until the dog reacts.
*It is vital to remember that the dog’s stress reaction is based on his own learning experiences, fears, personality and ability to cope. It is not based on things we may consider to be worrying to him!
Stress Needs Time to Reverse
Whilst the stress reaction may appear quickly and the dog’s brain fast forwards to reactivity, it goes slower when it moves in reverse. This is where trigger stacking comes in. A big stress trigger can take a dog thirty-six hours for recovery. If we add more stress triggers, whilst the dog’s brain is in reverse, the brain goes into an unhealthy forward and reverse battle. More stress triggers mean more arousal and eventually the dog will reach his limit (threshold) and react.