Can we talk? No, we mean really talk?
Good. Because that's what this novel really wants us to do. Talk.
Communication barriers can really cause problems – especially when cultures come into conflict. Misunderstanding and miscommunication have pretty serious and violent consequences, as we learn in the book. However, human communication is one of the strongest bonds that people can have. Island of the Blue Dolphins suggests that trying to communicate with others – not just speak, but really understand, each other's language – can bring hugely different cultures and people together.
Communication brings people together.
Communication is a lot more than just language; people who speak different languages can still communicate.