What does Pat Parelli teach about the relationship between the bit and the horse's emotional state?

Pat Parelli's teaching on bits and emotional state is built on a principle he states directly: the bit does not make the horse behave. The horse's emotional state — whether it is confident and calm or fearful and reactive — determines whether any bit can be used effectively. A frightened horse is not manageable through a stronger bit; it is a horse that needs its emotional state addressed before any bit communication is possible. Parelli identifies this as one of the most common errors in horse management: attributing behavioral problems to equipment and solving them by changing equipment. A horse that bolts in a snaffle is not likely to be safer in a stronger curb — it will bolt in the curb with more head tossing, more bracing, and more resistance added on top of the original problem. His Horsenality system is particularly relevant to bit selection because different emotional types respond differently to bit action. A Right Brain horse — one that is reactive and fearful — needs the lightest possible bit that can communicate clearly, because adding any more discomfort or complexity to a reactive horse's experience escalates rather than reduces its reactivity. A Left Brain horse — one that is confident and dominant — may need a bit that communicates more clearly because it will simply ignore a bit that does not get its attention. Parelli's broader teaching is that bits are communication tools, not control tools, and that any bit works well on a horse whose emotional state is calm and whose training is correct, while no bit works reliably on a horse that is not emotionally ready to receive its communication. This is why he spends significant time developing the horse's emotional fitness — its ability to remain calm and responsive in various environments — before considering bit progression.