Most people will say that Natural Horsemanship is like some magical doorway into the mind of a horse; they will tout people like Pat Parelli and Monty Roberts as being the "inventors" of training methods that are like nothing anyone has ever seen before. I know people who spent hundreds of dollars to go and watch clinics done by these people, and without fail they come home with arm-loads of "devices" (like Parelli's "carrot stick" and Robert's "Dually Halter"), books, videotapes, signed hats and shirts...and in the end, they are no closer to that "magic doorway" with their horse, though their pocketbook is significantly lighter.
The centuries old methods of Natural Horsemanship can be learned; the basics and application, without spending tons of money on "gadgets" and "videos". Though there are hundreds of variations of Natural Horsemanship, it basically boils down to the following five basic principles.
Horses have been around for many thousands of years. They have a particular social structure and certain instincts that have allowed them to survive in the wild. They have a distinct social structure which allows for an "alpha", or dominant, animal and those who are beneath him/her in the hierarchy.
The horse has a very highly developed communication system that deals mostly in body language. A horse knows by the "body language" of his herd mates whether or not he is in danger or being accepted in his current behavior.
Horses are "flight" animals, which means that their instincts dictate that they respond to negative or "scary" behavior by "running away" rather than by standing and fighting.
Any human who wants to interact with a horse must understand the basics, and eventually the intricacies, of the horses' natural body language and communication in order to make the horse "understand" you in a way that he understands.
Horses do not like to be "pressured", they respond to positive and negative stimuli. Natural Horsemanship is the method of rewarding good behavior with a "release" in pressure and punishing negative behavior with an increase in pressure.
An example of these principles applied in an everyday situation is as follows... You are trying to load a horse into the horse trailer. You walk him up to the trailer and he steps in without problem, you reward him with a "treat" (this is positive stimuli).
On the other hand, if you walk a horse up to a trailer and he balks, you might step him back a few steps and force him to trot in a few small circles and then quickly ask him to enter the trailer again. If he doesn't respond, you keep the "pressure" on until he steps in, at which point you "release" the pressure. The horse learns that when he is cued he should respond favorably if he wants you to treat him favorably.
In the end, Natural Horsemanship is simply a fancy term for understanding the "language" of a horse and teaching him to understand your language. If you want to go to a clinic, if you want to see someone "perform" for you for a nice, large fee, then by all means, check out the clinicians who are listed as Natural Horsemanship teachers, but if you simply want to learn to better communicate with your horse and have a better relationship with him, study the principles described above in more depth and you will be well on your way to creating your own unique variation of Natural Horsemanship...minus the expense.