They say that yorkies get 90% of their temperament from their mothers. What was his mother's personality like? Chances are she was just like him. I think there are certain traits that are innate or inborn and they are not going to change. They are just like people on that way. There is a basic framework to a personality that people are born with and you aren't going to change those basic traits.
He could improve over his lifetime though if he comes to feel more and more secure and as the scariness of puppyhood goes away and he mellows.
He sounds like a sweet dog though. |