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.
A well trained SAR dog is a sight to behold. The dog can evenly maneuver the most difficult of terrain with the grace of a mountain goat all the while looking for a trapped or hidden human being. This type of work is often done on the fly, at the drop of the hat, with little advanced warning. It requires a talented dog and a special handler willing to invest the time and effort.
Herding is one of oldest canine activities available. It has real world applications and is still in place for viable farm assistance in many places. For urban individuals, herding has become more of a training activity for competition for those breeds of dogs with natural instinct.