I don't know that I would say they are as smart as humans are. If so, I would expect to see them running around in lab coats studying us, don't you think? Seriously, dolphins do register way high on the intelligence scale, but how high is still an issue yet to be resolved. They demonstrate plenty of intelligence in learning aquired behaviors. Navy divers have long used dolphins to monitor and defuse volatile situations underwater. Dolphins are the stuff of legend, stories being told of long ago working with humans at sea. Their enlarged cranial capacity is one thing that would probably make them predisoposed to a superior intelligence in the animal world. Dolphins have long been a staple attraction at SeaWorld, both regular dolphins and their relatives, the orcas, or killer whales. So the jury is still out as far as how intelligent they actually are.
I think that dolphins are smart and they have shown that but some people say that human are more advanced than dolphins. As humans we have done some very amazing accomplishments that are impossible for any other species, however, dolphins have great minds and qualities. I would say we are equal and different in both ways.
Well, their brains, of course. Dolphins have large brains for their bodies -- in fact, a bottlenose dolphin is second only to humans in the ratio of brain size to body size. Researchers have also pointed to the parallels in the organization of dolphin and primate brains as more evidence of high intelligence in dolphins. Some have gone so far as to suggest that dolphins actually have a language that humans simply cannot comprehend.
They are excellent mimics of sounds and clearly communicate with one another, but does that mean they "talk?" No one less than Aristotle once wrote, "The voice of the dolphin in the air is like that of the human in that they can pronounce vowels and combinations of vowels, but have difficulties with the consonants." But a more scientific analysis of dolphin sounds suggests that for all their communication skills, dolphins lack the repertoire to have anything approaching language as we know it.
I believe dolphins are very smart, however I don't believe dolphins are as smart as humans. We are the most advanced species on this planet, and compared to our accomplishments, they are definitely not as intelligent. Over the past thousand years, so many advancements have taken place for humans, biological, technological, and more. For dolphins, while they have adapted and changed, there "accomplishments" are far fewer than our own.
Hope this helps!