I believe whales must be very intelligent, think of how massive their brains are. But they are trapped in the sea with a body that doesn't do much but take up space, so they don't have the physical ability to do that many things. Also they could simply not share the same interests and curiosity as humans do, maybe they just don't care about anything but eating, sleeping, and swimming, and their potential brain power goes unused..who knows
RE: What if Animals Were as Smart As Humans?