Final answer:
Historical linguistics, which examines how languages transform over time, is a true aspect of the field. It focuses on linguistic relativity and considers various factors that contribute to language change.
Step-by-step explanation:
Historical linguistics is indeed the study of language change through history. This is a true statement. Historical linguistics examines how languages evolve over time, which involves tracking changes in phonetics, grammar, semantics, and syntax. The divergence in languages can be attributed to a variety of factors such as migration, political changes, and environmental differences, but not to differences in brain structure amongst different groups of people. Understanding historical linguistics allows us to appreciate the dynamic nature of language and its role in shaping cultural and societal structures. It also highlights the concept of linguistic relativity, where language both influences and reflects cultural realities. Assessing linguistic change requires careful analysis since mere phonetic similarities are not sufficient proof of languages being related due to the vast complexities and variables involved.