The aim of good training is to expand the horse’s ‘window of tolerance‘ so the normal, every day stressors don’t bother him so much and there is room for his nervous system to take in and process unexpected or new experiences.
Horses are always moving between arousal states, from more aroused to less, and this often occurs within the window of tolerance so riders don’t often notice the process. But when these stimuli stack too high, they fill up the window and push the horse over the edge.
The rider’s reaction to that will either help to expand the window of tolerance, or push the horse farther above the threshold.
Growing the window can be done using three concepts: pendulation, titration, and self-regulation.
A pendulation is a swing or a cycle. It is returning to the point you started from. This tool to grow the window of tolerance requires patience. It takes time for the horse to return to a parasympathetic nervous state after being pushed up to or above the threshold of his window of tolerance and into a sympathetic state.
Adrenaline is the result of being pushed too far, and the half-life of adrenaline in the body is about 2.5 minutes. Allowing for a full pendulation of the horse’s nervous system then will take at least that long. Some wise old cowboys would call this ‘giving the horse some time to think’.
Trying to control the horse in a situation of high arousal can actually stack more stimuli up and push him over threshold. But this isn’t to say that you should leave your horse alone in a frightening situation. Backing off to where everyone was last comfortable, remaining calm, being reassuring, and waiting for signs of returning to a lower level of arousal is helpful. Being aware of stimulus stacking and trying to avoid stacking too high in the first place is even better. This takes time and practice.
Titration is a concept in where the balance is continuously adjusted by very tiny increments. In horse training, this is seen in progressing in a logical fashion through training, building in small steps through the training scale.
It can also be used when you start to see signs of stress responses in the horse. Consider what might be causing the response. Then use a tiny amount of that cause, not enough to make a response. Wait for pendulation and add a tiny bit more. In this way, the horse’s window of tolerance grows and expands through thoughtful training.
This part is for the rider or trainer and not so much for the horse. Horses are actually quite good at self-regulation within their window of tolerance, which is why stress responses often seem out of the blue to riders.
Taking a step back from training when you feel yourself becoming annoyed can help to give clarity to the situation before you and your horse get pushed about threshold. It is better to take the time to grow the window than to risk narrowing it by doing the same old things in the same old way.
Draaisma, Rachaël (2018) Communication Ladder: Recovery after Tension and Shock. In: Language Signs and Calming Signals of Horses, Taylor & Francis Group.
Thompson, Kirrilly. (2020) Growing your Horse’s Window of Tolerance. Horses and People, May-June.