Most buyers will also be in an emotional state. If you can remember that you are selling not just a piece of property but also an image, a dream and a lifestyle, you'll be more likely to put in the extra effort of staging and perhaps some minor remodeling to get top dollar for your home.
The branch of linguistics concerned with linguistic performance, that is, the production and comprehension of speech (or of sign language by the deaf), is called psycholinguistics. Psycholinguists also investigate how children acquire the complex grammar that underlies language use.
A linguist is someone who studies language. Linguists study every aspect of language, including vocabulary, grammar, the sound of language, and how words evolve over time. The study of language is called linguistics, and people who study linguistics are linguists. Being a linguist isn't easy; you usually have to go to graduate school and conduct research about a specific aspect of language. There are computational linguists, forensic linguists, comparative linguists, and many other specialties.