I'm not sure about why your dog might be doing this... though I think Belgians are definitely a step above, so he might be right about that! ;-)
My Tervuren male is tail wagging happy to meet anyone, human, animal or bird, and loves to play with anyone who will! He's got a terrific temperament and socializes well, and that is a big blessing!
Your dog might be more shy, making him reserved acting, or he may not have been socialized extensively as a pup, resulting in this behavior as an adult.
But, no, in my experience this isn't really a breed thing... more personal, I'd say!
Hope this helps,
Answered by TrueKnightTervurens - 3/5/2014 1:58:35 PM