In the training of horses, some may be taught intelligent refusal, in which they learn to analyze a situation to determine whether or not it is unsafe, and to take action accordingly. A horse which has learned intelligent refusal will not do something which it deems to be unsafe. This training technique is also used to train service animals like guide dogs.
Horses are naturally intelligent, sensitive animals, although some breeds can be a bit high strung. Like many ungulates, they also have a very refined sense of danger, thanks to thousands of years as prey to larger animals. They are also attuned to small changes in the natural environment which could signal things like unstable ground, dangerous ice, or loosely rooted trees which could fall. When intelligent refusal is integrated into a training program, it takes advantage of these natural horse traits.
In addition to protecting the welfare of the animal, intelligent refusal also protects its handler. In the case of guide dogs, for example, a dog will not cross the street when it is not safe. In the case of a horse, intelligent refusal might involve not taking a jump which is too high, or refusing to wade or swim a river with a dangerous current. A horse which has learned intelligent refusal will be a safer, more secure mount, especially for younger and more inexperienced riders.
Some horses, especially ponies, are innately smart about the dangers of potential activities, and the principle of intelligent refusal does not need to be taught because the horse will simply refuse to do dangerous things by nature. In a sense, intelligent refusal could be thought of as common sense for horses. In the case of ponies, riders need to learn to distinguish between intelligent refusal and a simple desire not to do something, although a well trained pony should not refuse a safe command once it has been given.
The concept of intelligent refusal is often integrated into natural horsemanship and other holistic horse training techniques. It assumes that horses should not ignore their innate intelligence and centuries of evolution, and that an active decision on the part of the horse to be smart in a particular situation could be extremely useful. While horses have a history of intelligent refusal in extreme circumstances, trainers attempt to hone it, teaching the horse that it is appropriate to ignore or refuse a command in certain situations.