Does Language Define Our Identity?

During break I saw the new Sherlock Holmes movie. In the Sherlock Holmes film, the main characters, Sherlock Holmes, Dr. Watson, and the gypsy woman Simza were very different from each other. The way Sherlock Holmes and Dr. Watson spoke, sounded like they were more intelligent. They used strong vocabulary, different codes for letters and other examples through out the movie to solve things and I think that it does mold and define their identity, because of the way that they speak, it makes them seem more brilliant then the woman gypsy when she speaks. Simza, the gypsy woman also grew up in a different background which also has to do with culture. She is a gypsy fortune teller and the way she spoke was not like she was as intelligent as Mr. Holmes or Dr. Watson. She talked like she grew up in a rural poor area, and she also was a gypsy which also affects how she speaks. She used lots of slang and so I think that defined her identity and made her the way she was in the movie as a gypsy fortune teller. On the other hand her identity of being a gypsy fortune teller could be the reason why she speaks with lower intelligence and uses a lot of slang. Maybe because of the people she is around it effects the way she speaks. She could be around poor, lower class people when she is telling fortunes, or with other gypsies, etc.  This also has to do with the power of a group of people affecting the way she speaks. Which ties the question of the power of a group of language users effect the use of language. Overall I think language can define our identity but I also think that our identity can define our language. It could go either way for the example that I used.