Researchers at the University of Toronto have pointed out that teenagers risk familial censure and ridicule of friends if they use slang. But IM allows them to deploy a 'robust mix' of colloquial and formal language.

They based their conclusions on an analysis of more than a million words of IM communications and a quarter of a million spoken words produced by 72 people aged between 15 and 20.

The researchers have argued that far from ruining teenagers' ability to communicate, IM lets teenagers show off what they can do with language.

In the photograph: A boy sends an sms from his phone from a premiership football match

Photograph: Getty Images