Personality
German Shepherds are highly intelligent and agile dogs with a strong work drive. They are often deployed in various roles such as police work, guarding, search and rescue, therapy, service-dog, and in military applications. The "ideal" German Shepherd should be alert and fearless in defense of its den and pack, but loving and non-aggressive within the home environment.
The breed has a personality marked by direct, fearless willingness to protect what it considers its "den" (i.e. house, car, and property in a home situation) and "pack" (i.e. human family in a home situation). It is poised, but when the occasion demands, eager and alert. Both fit and willing to serve in its capacity as a companion, watchdog, guide dog for the blind, herding dog, or guardian, whichever the circumstances may demand.
Trainability
This breed needs owners who are naturally authoritative over the dog in a calm, but firm, confident and consistent way. A stable, well-adjusted, and trained dog is for the most part generally good with other pets and excellent with children in the family. They must be firmly trained in obedience from an early age. German Shepherds who have passive owners and or who's instincts are not being met can become timid, skittish and may be prone to fear biting and develop a guarding issue. To be successful pets, these dogs should be trained and socialized from an early age with a firm and loving hand.