Dolphins do have fairly large brains. There are many stories, ancient and modern, about dolphins saving sailors from drowning. Ever since the film Flipper, we have all seen how clever they are at learning how to do tricks. However, the truth is that dolphins are no more intelligent than rats, which can also be trained to do tricks. The story about them rescuing people are true, but automatically rescue anything which is about the same size as themselves. Sometimes, they kill sharks and then immediately try to rescue them.
