Are all terrier dogs smart?

My puppy seems to be pretty intelligent. Are all the types of Terrier dogs smart or is it just certain ones. The Jack Russel on Frasier was incredibly smart, but my friend told me that his was dumb as dirt. His wasn't pure breed though.

I'm srry but I dont believe that any breed of dog is the most intelligent or that all dogs of that breed are....its just like humas....little kids watch what their parents do....dogs do the same they pay attention to their owners...we had dogs a lot of the time and thats what they would do and its like when we make mistakes we sometimes learn from them but sometimes we dont the same goes for dogs...I had a dog that wasnt considered a very smart breed and he was full bred and he was very very smart