Sociolinguistics is the descriptive study of the effect of any or all aspects of society, including cultural norms, expectations, and context, on language and the ways it is used. It can overlap with the sociology of language, which focuses on the effect of language on society. Sociolinguistics overlaps considerably with pragmatics and is closely related to linguistic anthropology.
Sociolinguistics' historical interrelation with anthropology can be observed in studies of how language varieties differ between groups separated by social variables (e.g., ethnicity, religion, status, gender, level of education, age, etc.) and/or geographical barriers (a mountain range, a desert, a river, etc.). Such studies also examine how such differences in usage and differences in beliefs about usage produce and reflect social or socioeconomic classes. As the usage of a language varies from place to place, language usage also varies among social classes, and it is these sociolects that sociolinguistics studies.
Sociolinguistics can be studied in various ways such as interviews with speakers of a language, matched-guise tests, and other observations or studies related to dialects and speaking.
The social aspects of language were in the modern sense first studied by Indian and Japanese linguists in the 1930s, and also by Louis Gauchat in Switzerland in the early 1900s, but none received much attention in the West until much later. The study of the social motivation of language change, on the other hand, has its foundation in the wave model of the late 19th century. The first attested use of the term sociolinguistics was by Thomas Callan Hodson in the title of his 1939 article "Sociolinguistics in India" published in Man in India.
The study of sociolinguistics in the West was pioneered by linguists such as William Labov in the US and Basil Bernstein in the UK. In the 1960s, William Stewart and Heinz Kloss introduced the basic concepts for the sociolinguistic theory of pluricentric languages, which describes how standard language varieties differ between nations (e.