There's a saying in the horse world that every time you work with your horse, you are either teaching him something or un-teaching him something ...
Learning theory is a summary term for what is known from psychology and horse behaviour about how animals (in this case, horses) learn and respond to training.
There are 4 quadrants involved in learning; positive reinforcement, negative reinforcement, positive punishment and negative punishment. Each of these quadrants ends with a consequence that can make the behaviour more or less likely.
Why is it so important for horse owners and riders to become educated about learning theory and its practical application? Because, knowingly or not, in each single encounter with horses we use learning theory tools from our training toolbox. Sometimes, riders pick the wrong tools from the toolbox, or do not know how to use the selected tool correctly and, due to this, horses may suffer (often silently) and become ‘naughty’, ‘unwilling’, ‘difficult’, or even dangerous to handle. Often, horses simply do not understand what the trainer wants from them, either because the trainer does not understand how to use cues correctly, or because they do not know how to reward ‘correct’ horse behaviour timely or predictably so that the desired learning outcomes can be achieved.
Training is all about bringing the right message across in fair and meaningful dialogue between horse and trainer.