Many Britons are welded to their smartphones 24 hours a day and refuse to turn them off in cinemas and theatres, according to a study Thursday showing how the devices are changing social behaviour.
Research for telecommunications watchdog Ofcom showed that more than a third of adults and a majority of teenagers say they are highly addicted to devices such as the iPhone and BlackBerry, often referred to as 'CrackBerry' by users for this reason.
Users are more likely than owners of standard mobile phones to never switch them off, and are more inclined to continue sending email or text messages even when at the cinema or the theatre.
They are also more likely to be hunched over their phones during social occasions such as meals with friends, the research showed.
Smartphones also encourage users to make more calls and send more text messages than regular mobile phone owners.
More than a quarter of adults and nearly half of all teenagers in Britain now own a smartphone.
And people who had bought a smartphone reported they had cut back on activities such as reading books and newspapers and watching TV.
A clear sign of their growing influence can be seen in their intrusion into holiday time, with users admitting they were more likely to take calls or consult emails from the office even when away.
James Thickett, director of research for Ofcom, said the insistence on keeping smartphones switched on in cinemas and theatres raised issues of social etiquette and tolerance.
"It raises an issue about social etiquette and modern manners and the degree to which we as a society are tolerant of this behaviour," he said.
"I think what we have found before is that teenagers have always been more likely to use mobile phones in cinemas and theatres.
"What we are finding now is that for smartphone users, it is much, much higher, but adult smartphone users as well.
"So it is not just about adults and teenagers having different values, it is about technology driving the values towards the way you behave in social situations."