Language has a fundamentally social function. Processes of human interaction along with domain-general cognitive processes shape the structure and knowledge of language. Recent research in the cognitive sciences has demonstrated that patterns of use strongly affect how language is acquired, is used, and changes. These processes are not independent of one another but are facets of the same CAS (Complex Adaptive System) […] The CAS approach reveals commonalities in many areas of language research, including first and second language adquisition, historical linguistics, psycholinguistics, language evolution, and computational modeling.