Most UK children own a smartphone by 11, and getting one youngest went with worse mental health later

When the phone arrives

In autumn 2024 Ofcom asked 2,480 UK parents whether their child had a smartphone of their own¹. At 10, 58% did. At 11, the age most children start secondary school, it was 89%, and by 13 it was 97%¹. The step from 10 to 11 is the sharpest on the chart. For most UK families the phone comes with the new school bag.

Each single age rests on 133 to 217 parents, so the dip at 9, below 8, is probably noise¹. The age groups are steadier. 17% of 3 to 5 year olds owned a smartphone, 40% of 8 and 9 year olds, 79% of 10 to 12 year olds and 96% of 13 to 15 year olds¹. The US looks much the same. A 2021 Common Sense Media survey of 1,306 young people found 43% of 8 to 12 year olds and 88% of 13 to 18 year olds had one². Parents answered the Ofcom survey, not children, so these are the phones parents know about¹.

Does the age of the first phone matter later

If nearly every child has a phone by 11 or 12, the next question is whether getting one at 6 or 8 is any different. Sapien Labs tried to answer it with a 2023 online survey of 27,969 people aged 18 to 24³. It asked them at what age they got their first smartphone or tablet, and scored their mental health on its own 47 item questionnaire. A score below zero, on a scale that runs from minus 100 to 200, counts as distressed or struggling³.

74% of women and 42% of men who got their first phone or tablet at 6 scored as distressed or struggling, against 46% of women and 36% of men who waited until 18³. For women the line runs downhill almost the whole way, with 61% at 10 and 53% at 12³. For men the gap was much smaller, and their numbers bounce around, with those who got a phone at 13 scoring worse than those who got one at 12³.

A 2025 journal summary by Thiagarajan, Newson and Swaminathan covered more than 100,000 people and found the same pattern for suicidal thoughts⁴. 48% of women and 31% of men who got a phone at 5 or 6 reported them, against 28% of women and 20% of men who got one at 13⁴.

We would not lean on these numbers too hard. People were recruited through online ads, not at random, and were measured at one point in time³. They recalled the age of their first phone years later, and the report does not look at what they did on it³. The report comes from Sapien Labs, which runs the survey and its questionnaire, and Sapien Labs published it itself, not in a peer-reviewed journal³. Still, the direction for women holds across six age points, and the larger summary points the same way⁴.

What parents do not see

A phone in a child's pocket is a screen most parents never look at. The clearest measure of that gap is older than the smartphone era. In 2010 EU Kids Online interviewed 25,142 internet-using children aged 9 to 16 at home in 25 European countries, along with one parent of each⁵. Children answered the sensitive questions on their own. 14% said they had seen sexual images online in the past 12 months⁵.

Their parents were asked the same question. Among the children who said yes, 40% of parents said their child had not seen any, 26% did not know, and 35% knew⁵. About two in three parents of these children were wrong or could not say. Sexual images here include nudity, so this is broader than porn. The children were asked about the past year, while parents were given no time limit⁵.

Those interviews took place early in the smartphone era. Only 12% of these children went online with a handheld device such as an iPhone or BlackBerry⁵. Nine years later the gap was still there. A 2019 UK survey for the British Board of Film Classification asked 1,142 parent and child pairs about porn itself⁶. Of the 862 parents who thought their child had not seen porn, 53% of the children said they had⁶. That survey ran online, and its authors warn that some parents may have watched while their child answered⁶.

Taking the phone away at school

Many schools in England have tried a different fix and taken the phone out of the school day. Goodyear and colleagues compared 1,227 pupils aged 12 to 15 at 30 schools between November 2022 and November 2023, 820 of them at 20 schools with a ban and 407 at 10 schools that allowed phones⁷. During the school day the ban did what it says. Median phone use in school was 1 hour where phones were allowed and about 10 minutes where they were banned⁷.

Across the whole day the difference did not hold up. Pupils at schools with a ban reported a median of 4.5 hours on a weekday and 6 on a weekend day, against 4 and 5 at schools without one, and neither gap was significant after adjustment⁷. Most bans still let pupils keep the phone, switched off in a bag. Only 4 of the 20 schools made phones unreachable⁷. A ban covers one part of the day and leaves the rest to the child and the family, which brings us back to the parents who did not know.

Wellbeing told the same story. It scored 46 at schools with a ban and 48 without, on a 14 to 70 scale⁷. After adjustment the gap was 0.48 points, well under the 3 points the authors count as the smallest gap that matters⁷. Time on the phone went with wellbeing, and the school rule did not. Across all 30 schools, each extra hour of phone use on a weekday went with 0.53 points lower wellbeing and higher anxiety and depression scores⁷.

That sits beside the Sapien Labs finding, and like it, it cannot show the phone caused anything³⁷. The school study is a snapshot, and only about 1 in 10 of the schools invited took part⁷. Phone time was self-reported, and pupils at schools with bans may have under-reported use in school⁷. The survey also did not pick out pupils who had no smartphone⁷.

Why the timing is hard

The last piece is about the child holding the phone. Steinberg and colleagues tested 5,105 people aged 10 to 30 in 11 countries, among them China, India, Kenya, Sweden and the US⁸. Sensation seeking, measured with a gambling task, a driving game and a thrill-seeking questionnaire, peaked at 19 and fell after⁸. Self-regulation, measured with a Stroop test, a planning puzzle and a planning questionnaire, kept rising until it peaked at 24, with no significant change after 25⁸.

This was not one country's quirk. Sensation seeking rose and fell this way in 7 of the 11 countries, and self-regulation rose with age in 9 of the 11⁸. All the analyses controlled for parents' education and a reasoning test score⁸. On the questionnaire alone, those aged 10 or 11 called 56% of the thrill statements true on average, and those aged 18 to 21 called 62% true, the highest of any group⁸.

Set that beside the Ofcom numbers. Nearly 9 in 10 UK children own a smartphone at 11¹. The pull toward thrills keeps rising for years after that, and self-control is still growing into the mid-20s⁸. The first phone lands in the years with the least brake, and most parents of children who have seen sexual images online do not know it happened⁵.

The caveats here are real. On the questionnaire, the gaps between age groups were small next to the gaps between people, with standard deviations of 27 to 30 points in every group⁸. The study tested different people at each age instead of following the same people over time, and the parts of each combined measure barely agreed with each other⁸. It measured sensation seeking in general, not porn use. Only the BBFC survey in this article asked about porn directly⁶.

How they found it

• Ofcom asked 2,480 UK parents whether their child had their own mobile phone, and whether it was a smartphone. The survey ran from October to November 2024. A 2021 US survey of 1,306 young people asked the same of the young people themselves.
• Sapien Labs surveyed people aged 18 to 24 online with its own 47 item mental health questionnaire, and asked at what age they got their first smartphone or tablet. Distressed or struggling means a score below zero on its scale, which runs from minus 100 to 200.
• EU Kids Online interviewed 25,142 internet-using children aged 9 to 16 and one parent of each, at home in 25 countries. Children answered the sensitive questions on their own. A 2019 UK survey asked 1,142 parent and child pairs about porn.
• In the school study, pupils in years 8 and 10 at 30 schools in England answered questionnaires about phone and social media use, wellbeing, anxiety and depression. Most bans still let pupils keep the phone, switched off in a bag.
• Sensation seeking combined a gambling task, a driving game and a thrill-seeking questionnaire. Self-regulation combined a Stroop test, a planning puzzle and a planning questionnaire.
• The thrill-seeking analyses controlled for parents' education and a reasoning test score.

What it cannot tell you

• Parents answered the Ofcom survey, not children. Single ages rest on small groups, so small dips like 9 below 8 are noise.
• Sapien Labs recruited through online ads and measured at one point in time. Age at first phone was recalled years later. The report comes from Sapien Labs, which runs the survey and its questionnaire, and published it itself, not in a peer-reviewed journal.
• The EU Kids Online data were collected in 2010, when only 12% of these children went online with a handheld device, and sexual images include nudity, so this is broader than porn.
• The school study is a snapshot, so it cannot show the phones caused lower wellbeing. About 1 in 10 schools invited took part, and phone time was self-reported.
• The thrill-seeking study tested different people at each age, not the same people over time, and the parts of each combined measure barely agreed with each other, with correlations of 0.03 to 0.08.
• Apart from social media time in the school study, none of these studies tracked what children did on their phones. The thrill-seeking study measured sensation seeking in general, not porn use.

Sources

1. Ofcom. Children and parents: media use and attitudes report 2025. 2025.
2. Common Sense Media. The Common Sense census: media use by tweens and teens, 2021. 2022.
3. Sapien Labs. Age of first smartphone/tablet and mental wellbeing outcomes. 2023.
4. Thiagarajan TC, Newson JJ, Swaminathan S. Protecting the developing mind in a digital age: a global policy imperative. J Hum Dev Capabil. 2025;26(3):493-504.
5. Livingstone S, Haddon L, Görzig A, Ólafsson K. Risks and safety on the internet: the perspective of European children. Full findings. LSE, EU Kids Online; 2011.
6. Revealing Reality for the British Board of Film Classification. Young people, pornography and age-verification. 2020.
7. Goodyear VA, Randhawa A, Adab P, et al. School phone policies and their association with mental wellbeing, phone use, and social media use (SMART Schools): a cross-sectional observational study. Lancet Reg Health Eur. 2025;51:101211.
8. Steinberg L, Icenogle G, Shulman EP, Breiner K, Chein J, Bacchini D, et al. Around the world, adolescence is a time of heightened sensation seeking and immature self-regulation. Dev Sci. 2018;21(2):e12532.

Sources checked October 2026.