The German Shepherd personality is aloof but not usually aggressive. He's a reserved dog; he doesn't make friends immediately, but once he does, he's extremely loyal. With his family he's easy-going and approachable, but when threatened he can be strong and protective, making him an excellent watchdog.
This highly intelligent and trainable breed thrives on having a job to do — any job. The German Shepherd can be trained to do almost anything, from alerting a deaf person to a doorbell ring to sniffing out an avalanche victim.
One thing he's not good at is being alone for long periods of time. Without the companionship he needs — as well as exercise and the chance to put his intelligence to work — he becomes bored and frustrated. A German Shepherd who's under-exercised and ignored by his family is likely to express his pent-up energy in ways you don't like, such as barking and chewing.
Like every dog, the German Shepherd needs early socialization — exposure to many different people, sights, sounds, and experiences — when they're young. Socialization helps ensure that your German Shepherd puppy grows up to be a well-rounded dog.