How do you read whether a horse genuinely understands something or is just complying?

Distinguishing genuine understanding from compliance in a horse requires looking beyond the external behavior to the quality of the horse's engagement with the training and the conditions under which the behavior occurs, because a horse that genuinely understands a trained response will produce it consistently across varying conditions while a horse that is merely complying will produce it only when the specific conditions of the original training are replicated. The most reliable indicators of genuine understanding are: the horse producing the correct response with less pressure than was required to install it — indicating that the horse has internalized the communication rather than simply learned to endure a specific pressure level until it passes; the horse producing the correct response in new environments and with different trainers rather than only in its familiar training context; the horse showing the searching, engaged quality of an animal that knows what produces release and is actively seeking it rather than the shut-down quality of an animal waiting for pressure to stop; and the horse generalizing the response appropriately — a horse that genuinely understands the concept of yielding to pressure will yield more readily to a new form of pressure it has not been specifically trained to rather than yielding only to the specific training stimulus it has experienced. Tom Dorrance's concept of true unity — the horse and human thinking together rather than the horse simply responding to mechanical pressure — describes the endpoint of genuine understanding rather than mere compliance. Buck Brannaman's concern with the quality of the horse's response — its softness, its self-direction, its willingness — rather than simply the fact that the behavior occurs reflects the same concern with distinguishing genuine understanding from behavioral compliance. A horse that performs correctly but shows the physical signs of discomfort, anxiety, or shutdown in its performance has not genuinely understood the training but has learned to produce the desired output while remaining in an unresolved internal state.