of a new situation or new people is what causes most of this behavior.
To get them better socailized, take them out in public places, kids soccer or soft ball games, get them used to new noises, new faces, new sounds as much as possible.
This is often the case in dogs who are removed from their mothers before 12 weeks of age.
How old was your dog when you got him?
Did the breeder do any socialization when he was young?
These things are very important to a puppy to make them more sociable as an adult dog. You might have to do more training than usual in a fearful dog, but you can overcome this negative behavior.
Sue & Cricket
