Besides humans, dolphins are said to be the smartest animals on Earth — smarter, even, than any other primate. They have extraordinarily large brains in comparison to body size and exhibit exceptional levels of emotional and social intelligence. They have the capacity to communicate through language, solve complex problems, use tools, and remember a great number of pod members for long periods of time, just like humans.
Dolphins are highly social and have been proven to deeply care for and learn from one another. However, they're also acutely self-aware. They are one of the only known animals that can recognize themselves in a mirror.