The difference in attitude to humans between dog pups and wolf pups was dramatically demonstrated in a recent study:
In the study, the wolf pups were raised so as to trust humans and the dog pups were not. Yet the wolf pups did not trust humans — but the dog pups did.
“Yet, both sets of puppies were equally skilled at other tests of mental ability, Salomons said. It was only people-reading skills that the dog puppies were better at.” …
The results, while dramatic, should not be surprising. Humans have been breeding dogs for thousands of years. We have been intelligently designing them to depend on us, obey us, help us, and want our approval …News, “Why do dogs understand people better than wolves? ” at Mind Matters News
You may also wish to read: In what ways are dogs intelligent? There is no human counterpart to some types of dog intelligence.
The real reason why only human beings speak. Language is a tool for abstract thinking—a necessary tool for abstraction—and humans are the only animals who think abstractly.