Dolphins are commonly believed to be the second most intelligent animal, with only humans surpassing them. Some people may still argue that chimpanzees, bonobos or another great ape should hold that position, research suggests they lag behind dolphins. The brain to body size ratio seems to be very important in figuring intelligence. The bigger the brain in relation to the size of the body the more intelligent the animal. Humans have the largest brain, followed by dolphins; and chimpanzees come in third. Dolphins have been known to rescue people lost at sea, and learn easily. Chimps may have opposable thumbs, but dolphins don't really need them.
Large size is not the only thing dolphin brains have in common with human brains. Folds, or creases also exist. This allows for more brain area in less space, and is a sign of complexity. Great apes have shown an amazing ability to communicate. Dolphins must have at least equivalent capabilities. The question may not yet be answered, but more research is definitely needed. The intelligence of chimpanzees and the possibilities seen in dolphins is more than enough to justify attempts at communication and mutual learning. Dolphins have even been observed to suffer from emotional trauma and stress much as humans do. Particularly dolphins that have been brought in captivity.
There is a famous case of a dolphin in captivity, bringing a learned behavior back to the wild. A dolphin was taught to tail walk while recuperating in captivity, and upon its return to the wild, taught other dolphins to tail walk. The trick spread like a fad. Dolphins have been known to use primitive communicative signals, and coordination. Dolphins could possibly one day communicate with humans through whistling. Dolphins are capable of following commands, and they are capable of whistling themselves. This common ability could allow us to communicate better with them than even the great apes. Dolphins are undoubtedly extremely intelligent creatures. Their ranking may still be debated upon, but their potential is undeniable. Perhaps learning to communicate with and understand the other creatures we share a planet with, we could one day better understand an alien civilization. Whatever the purpose, and whatever the findings, dolphins deserve a closer look. Some scientists have even suggested that dolphins deserve the status of non-human persons. Until more is understood, this seemingly absurd notion cannot be discounted. Chimps have proven capable of communicating with us on a childs level, dolphins may be able to do even better.