At about 14 or 15 years of age, we see the development of more adult speech due to contacts beyond the home and school. During adolescence language use changes rapidly because of the dense social networks that teenagers form (Chambers, 1995:8). Then, in young adulthood, use of the standard form of language increases for those involved in occupations which are "language sensitive" (Chambers, 1995:159). However, another view is that children as young as four demonstrate social and stylistic variation even before they master the pronunciation and grammar of their language. (Labov 1989:96). This would suggest that variation occurs as part of the development of linguistic competence.