The personality of a dog is flexible and indeterminate. Dogs can be exuberant or shy; friendly or hostile; fearful or bold; aggressive or passive or some combination of the above. These differences in personality may to some extent be determined by breed, or individual genetics, but for the most part it is based on how and to what extent each particular dog has been socialized.
The origins of all training, such as Schutzhund or IPO, are based in Germany. These training tests were developed as a primary method of producing top level German Shepherd Dogs. They were geared to identify suitability of individual dogs for work in several formats
If you ever owned a dog when you were a child, you can probably recall the joy and exhilaration you felt every day, playing with your best buddy. Once you grew up and (assuming you) started a family, you probably wanted your kid(s) to experience the same things that you did. A loving, loyal, fun-loving animal companion is one of the best things in the world.