Interestingly, Piestrup (1973) reports that when white teachers "punished"
black children for speaking in non-standard ways, the children's use of black
speech forms increased during the course of their time at school; that is, they
accentuated their ethnolinguistic styles. The opposite was true in classrooms
in which the teacher did not punish the use of non-standard speech forms
and thereby threaten the pupils' positively-valued distinctiveness.