The ability to learning and perform behaviors in a horse is similar to learning and performing in humans. They are based on base needs.
In 1943, Maslow suggested a theory that there are a base of needs upon which all other levels function and that each of the higher levels cannot happen unless the ones below them are met. He created a triangle of needs. Below is slightly modified from his original theory to fit for horses.
At the peak of the triangle is learning and performing (creativity, problem-solving etc).
Next is self esteem (feeling capable, confident, respectful of others).
Next level down is safety, security, belonging (access to resources, health, friends, family).
At the bottom is Physiological needs; breathing, eating, drinking, sleeping, warmth/cool, defecation)
Before a horse can learn or perform, his basic needs must be met. They far over-ride any other needs. If your horse is tired from a long ride, already full from grazing all day before you train, thirsty, or hot from standing in the sun, he will not be able to learn or perform. What can you do to fill these needs before asking his to train or perform?
Have a look at the list we created in post 13. Which of those reasons for not performing are related to physiological needs of your horse not being met?
Which are related to basic safety, security, belonging needs?
Which are esteem-related?
What can you do to change each for your horse?
Only when all of these are in place (from the bottom of the triangle on up in order) can the horse learn or perform a known behavior.
Since each horse varies in its needs, filling those needs will be different for each horse. Horses that have a sensitive nature will require different levels of adaptation on your part (likely more) than a horse with a resilient temperament.
Next time, when you have a problem with your horse, reflect on which of his needs are not being and what you can do to help your horse meet them so he can succeed.