The locus of language change in the life course of speakers

The central question addressed by this paper is the articulation between language change in the historical sense, and change as experienced by individual speakers. Research in cognitive science has made it clear that the critical period is a watershed in the construction of individual grammars (e.g. Newport 2002). In keeping with these findings,linguistic theory has generally associated grammatical instability with the period of first language acquisition in childhood. A related assumption is that individual grammars are stable after L1 acquisition. As a corollary of these assumptions, most current literature modeling language change locates it within the scope of first language acquisition (e.g. Lightfoot 1999). Another body of research, framed largely within a sociolinguistic perspective, has argued that adolescence is the time when individual speakers reshape their grammars under peer group influence (e.g. Eckert 1999; Labov 2001). Studies of the speech of young children and of adolescents have, however, not been designed to address the question of language change nor, by and large, does most such research reflect in any direct way on the critical period.

Taken in tandem, two kinds of longitudinal research can provide direct evidence of the relationship between lifespan change and language change. This is the focus of my current longitudinal research on spoken French in Montreal between 1971 and 1995, an NSF-funded study entitled “Language Change across the Lifespan”. Data from a panel of 60 speakers was gathered in 1971 and 1984, and 12 of these same people were the subject of a restudy in 1995. Comparisons of this panel across the individual lifespans can provide a picture of stability vs. change in adult life. Trend comparisons can be made by studying a matched sample of different speakers at the same periods. Thus it is possible to relate change or stability in the language to change or stability in individual speakers followed across the 24-year span of the study. Though a majority of speakers show the expected adult stability, a sizeable minority have experienced significant changes across the lifespan well into adulthood and even middle age. Extreme social mobility appears to be associated with the ability of adults to make significant changes. Strong social motivation is thus a factor, but with limits in later life. These trends will be located in four linguistic changes in Montreal French, involving phonetics, morphology, and the tense and aspect system. Each of these follows a different trajectory and, taken together, enable us to outline a number of hypotheses for future research.

The paper concludes with a discussion of the implications of this research for more general questions involving the modeling of language change, and the relationship between cognitive and social factors. Among other issues, I will consider the nature of post-critical period change in general; the distinction between transmission and diffusion (Labov n.d.); and the locus of different kinds of competition (grammar-internal vs. competing grammars, cf. Kroch, Taylor & Ringe 2000) as related to the lifespan.

References:
Eckert, Penelope 1999. Linguistic Variation as Social Practice Oxford: Blackwell.

Kroch, Anthony, Ann Taylor & Don Ringe. 2000. The Middle English verb-second constraint: A case study in language contact and language change. In Herring, Susan C., Pieter Van Reenen & Lene Schosler [eds], Textual Parameters in Older Languages, Amsterdam: Benjamins, pp. 353-391.

Labov, William. 2001. Principles of Linguistic Change. Volume 2: Social factors. Oxford: Blackwell.

Labov, William. n.d. Transmission and diffusion. In press, Language.

Lightfoot, David W. 1999.The development of language : acquisition, change, and evolution. Oxford: Blackwell.

Newport, Elissa L. (2002). Critical periods in language development. In L. Nadel (Ed.), Encyclopedia of Cognitive Science. London: Macmillan.