Usually dogs like that have been beat pretty good but sometimes it just takes some TLC or a little more attention.. not saying you dont but thats just what it sounds like. I have a dog kindda like that but hes been like that since he was a puppy on the ride home he winned the whole way. But with time hes gotten over it.
i dont think thats true at all just because its skiddish dont mean it has been beat. i think its genetics most of the time. i have seen dogs bread that were spooky and all the pups were the same way. most dogs will grow out of it but it does take alot of time.