First, why are they necessarily correlated? They could be two functions that happened for different reasons at different times. You'd have to be more specific by what you mean by languages and how you're determining self-awareness. Sometimes, I don't think some humans are self-aware. :P Then you could extrapolate from animals. Some animals are said to be self-aware. From wiki, Apes and monkey have been taught to recognize human language effectively. Whether dolphins or magpies can understand language is debatable, but there's more evidence that they do communicate with each other. Teaching apes and monkeys language hasn't made them more self-aware. If they are self-aware, their language doesn't seem to have developed much in the same time that human language has developed. I think the ability to communicate self-awareness to others comes from the ability to express language, but that doesn't mean that animals aren't doing the same. Humans just can't understand them if they are.Studies have been done mainly on primates to test if self-awareness is present. Apes, monkeys, elephants, and dolphins have been studied most frequently. The most relevant studies to this day that represent self-awareness in animals have been done on chimpanzees, dolphins, and magpies. Self-awareness in animals is tested through mirror self recognition. Animals who show mirror self recognition go through four stages 1) social response, 2) physical mirror inspection, 3) repetitive mirror testing behavior, and 4) the mark test; which involves the animals spontaneously touching a mark on their body which would have been difficult to see without the mirror.