There is a concept in sociolinguistics called accommodation theory and it is tightly connected to the concepts of prestige and negative prestige. Studies have shown, for example those in Denmark, that children, young people, and teens may be motivated to accommodate negative prestige (or positive prestige) aspects of sociolinguistic behavior based upon television programing they watch (believe it or not!) in a sociolinguistic dynamic.
[Sociolinguistic dynamic is how social behavior and interaction is expressed by yet influenced by language in an influence that goes both directions, from speaker to society and/or from society to speaker.]
What the first paragraph means is that the sociolinguistic dynamic witnessed in television shows can dominated sociolinguistic reality in daily experience and that this dominating influence can be favorable as prestige, as in upholding national linguistic standards such as preserving diversity of dialects (as is desired in Denmark), or it can be unfavorable as negative prestige, as in spreading the East London dialect to areas far removed from East London (as is occurring in England).
All this is to suggest that it is possible this/these group/s at school are experiencing the effects of interpersonal accommodation theory [they are influenced either favorably or unfavorably by a sociolinguistic dynamic they are experiencing, such as one or some television show or shows] as studies in Denmark and England have shown to be possible.