Mission Heights Junior College student Shaania Lai says she doesn't use her phone as much as her younger brother. Photo / Dean Purcell
A third of Kiwi high-school students feel they are spending too much time on their phones - but can't stop themselves.
An online "census at school", filled in by more than 23,000 children so far this year between Years 4 and 13, has found that students in everyyear of high school spend a median of three to four hours on screens every night after school.
A third of them in the first year of high school, rising to almost half in their final year, are on screens for almost four hours a night.
And 35 per cent of the 10,600 high-school students in the survey said they spent "too much" time in front of screens on their phones.
Half said the time they spent on their phones was "about right", 6 per cent said it was "too little" perhaps because of parental restrictions, and the rest either did not have phones or didn't answer the question.
Shaania Lal, an 11-year-old at South Auckland's Mission Heights Junior College who has just got her first phone in the past year, said her older brother got his first phone in Year 6 "because he was literally begging for it".
"I just use it for texts and sometimes I play games and stuff. I'm not allowed to play games on weekdays and the maximum is one hour on the phone after school.
"I don't want to use social media and I'm not allowed to, because I've heard so many stories like these guys are texting and meeting each other and they might get kidnapped or something."
The census has found a steady increase in after-school screen time with age from a median of one to two hours in primary school to two to three hours at intermediate age and three to four hours in high school.
Netsafe education director Sean Lyons said parents needed to judge how much screen time to allow for each child.
"I'm not sure there's an ideal amount," he said.
"Very early on there were recommendations about screen time, but a lot of those recommendations were based on TV and when we believed there was a right amount of exposure to that sort of one-directional broadcast media.
"We now use screens in a very different fashion and we now need to be cognisant of the kinds of activity that people are involved in."
The students themselves have strong views on the activities they are spending too much time on, which are strikingly different for boys and girls.
Almost a third of the boys (31 per cent), but only 9 per cent of girls, across the full sample from Years 4 to 13 say they are spending too much time on video games.
Surprisingly, 51 per cent of girls, but only 19 per cent of boys, say they are actually spending "too little" time on video games, again presumably reflecting parental restrictions.
Conversely, 27 per cent of girls but only 13 per cent of boys feel they spend too much time on social media, whereas 23 per cent of girls and 32 per cent of boys feel they don't spend enough time on it.
The age pattern for social media shows an abrupt change at the start of high school. Primary and intermediate students are more likely to feel they don't spend enough time on social media, presumably because they are not allowed to, but students at all high school levels are more likely to feel they spend too much time on social media.
But the pattern for video games is the same throughout the age range, with students at every age actually more likely to feel they spend "too little" time on games.
The census shows that Instagram has displaced Facebook as the students' most popular social media channel at every year level except Year 13, where more than 90 per cent of students have signed up to both main channels.
One in seven students (15 per cent) has their own YouTube channel to upload content by Year 5, rising to 20 per cent by Year 8 but then falling back to about one in seven in high school.