Consider the following statements regarding the geographical study of language:

1. Language distribution often reflects historical migration and cultural diffusion processes.
2. 
   
3. Linguistic diversity tends to be higher in regions with long-term geographic isolation.
4. 
   
5. Political boundaries always coincide with linguistic boundaries.
6. 
   
7. Geographers study language to understand cultural regions and identity formation.
8. 
   

Which of the statements given above are correct?