At first glance it makes perfect sense...
If I want to teach a horse to be responsive and "light" to my cues, I begin with the "lightest" request. If the horse responds, I "remove" the cue. This is known as negative or "removal" reinforcement. It is a real training tool and an effective means of communication between horses, humans, and all creatures. It's based on the principles of cause and effect. The learning occurs when the horse grasps the connection between the request that is being made and the behavior that makes the request go away.
What if the horse fails to respond correctly or at all? Traditional training instructs us to escalate the intensity of the cue or "ask harder." That might mean more physical pressure in the form of pushing, pulling, tapping, hitting, etc., or emotional intimidation (flag waving, hitting the ground with a rope or whip, etc.). Becoming quicker, louder, or increasing our own intent and energy are other tools that are often used to motivate the desired response. Intensity may increase slowly, rapidly, or be delivered explosively. This approach is considered "fair" because once the horse offers the behavior we want happen we release the pressure.
What's important to understand, and is sadly often ignored, is the experience the horse is having between the initiation of the request and the performance of the behavior. In other words, what is happening to him emotionally? How is he perceiving the situation? And, most importantly, is he learning a valuable skill or is he learning that the human is in charge and he is helpless? The reality is it's a lousy experience for the horse and we're the ones who are creating it.
We need to ask ourselves three questions when we ask our horse to perform for us. 1. Does my horse understand what I want? 2. Is my horse capable of doing what I ask? 3. How does my horse respond to my request? Making sure the answer to these questions are yes, yes, and calmly, willingly, and well, is our job as a trainer. If your horse doesn't respond at all or gives an incorrect response, that's our signal to stop and go back to the drawing board.
Just because we know what we mean and what we want our horse to do, doesn't mean that our horse grasps the concept or has the ability to respond. Translating your requests to your horse in a successful way is the challenge each of us face while working with our equine students. The most effective and successful approach is with a systematic process that keeps the learning center of your horse's brain active and engaged. That allows information to be received and processed and over the course of time desirable patterns behavior will develop.
When you resort to harder, faster, louder techniques, you are activating the fear center of the brain. You may ultimately get the response you are looking for but in doing so you are also causing emotional distress, physical tension, and putting a big strain on your relationship. Trust will erode and willingness will wane. Everyone wants to be treated with respect, understanding, and compassion, including your horse.
Instead of amping up the pressure, show your horse what you want in a simpler easier-to-understand way. In addition to making the request easier, be happy-happy with the smallest effort, then follow a slow and methodical path toward your ultimate goal behavior. In other words, lower the heck out of your expectations. We put way too much pressure on our horses to "perform" without noticing that we are sacrificing their emotional and physical well-being along the way. That is a crappy pattern of behavior we humans easily fall into. Our horses do NOT need to be intimidated, forced, and coerced into working with us. They WILL give us what we want and MORE when they are relaxed, comfortable, and motivated to participate. Our job is to help them find the experience engaging, stimulating, and make sure they feel safe along the way.