Define intelligence. Golden retrievers are dumb as a box of rocks, but they so want to please you that they are easily trained. I'm also not sold on border collies being the smartest. Great instinct isn't necessarily intelligence, either. Our smartest dogs were all mutts, mostly of the terrier persuasion. Terriers can add two and two and come up with four, then figure out the cube root, all while telling off the dog down the street. And while I loved my Belgian Tervuren to pieces, he wasn't exactly the brightest bulb on the Christmas tree. Beautiful instincts, incredibly devoted, not much in the way of brains.