The social mechanisms that influence the direction of language change operate along the demarcations of networks of communication (Bloomfield 1933; Milroy and Milroy 1985). Within geographic regions, the focused organizations that individuals participate in structure the lines of communication (Feld 1981) and the socio-demographic composition (social ecology) therein limits the options of peers to associate with (McPherson, Smith-Lovin, and Cook 2001). Schools have their own social ecology (McFarland et al. 2014) and attendance at schools can explain language change at a level above social interaction but below the level of community (Dodsworth and Benton 2017, 2019).
This study uses acoustic vowel measurements from 132 speakers in three geographically contiguous cities located in northwestern Wisconsin. Modeling results indicate (1) similar socio-geographic contexts lead to linguistic similarity; (2) dissimilarity in social ecology leads to greater linguistic dissimilarity as the difference between a dyads’ years of birth increases; (3) net of local socio-geographic context and social ecology, similarity in sex and age leads to linguistic similarity and vice versa. These patterns indicate that local social ecologies further demarcate the lines of communication thereby structuring the form of language at a level between the micro interactional and the macro level of the speech community.