Is your dog also a Lab? If so Labradors are retrievers bred to flush and retrieve birds on a hunt. Since there would be many hunters with their own individual dogs and they should not show aggression, they are bred to be somewhat friendly - that is good temperament for the breed and is preferable. That is not to say some Labs cannot show guarding instinct (Buckingham Palace uses Labradors for guarding). In any case the guarding instinct (Territorial) only shows up at almost full maturity in such breeds which in your case could be 2 to 2 1/2 years of age.