Growing up in Ireland: Children have social media profiles aged nine
Findings come on same day as warnings on cancer and tech use
The toll that technology is taking on children’s health was laid bare in separate reports linking screen time to 12 common types of cancer and short-sightedness.
Rising exposure to smartphones, tablets and gaming consoles in childhood is driving long-term weight gain – identified as one of the key causes of cancer, the World Cancer Research Fund found.
And every hour a day playing computer games raises the risk of short-sightedness by 3pc, research by King’s College London found.
And almost a quarter of nine-year-olds in the country have an online profile, according to worrying new findings that raise concerns about exposure to dangerous strangers.
Most parents have rules around content and amount of time spent on devices, but it hasn’t stopped many children using sites where 13 is supposed to be the minimum age.
According to their mothers, 23pc of Irish nine-year-olds now have social media or gaming profiles - 26pc of boys and 21pc of girls.
Boys' profiles are largely related to computer gaming, while for girls it tends to be social media, according to the Growing Up in Ireland report.
Online networking sites, such as Snapchat, are very popular with teenagers, while many younger children lie about their age in order to create an account.
The amount of time nineyear-olds spend watching TV or on other screen-based activities, as well as figures for online profiles, is one of the focuses of the report out today.
Latest findings from the Growing Up in Ireland study give a detailed snapshot of children born at the start of the recession in 2008.
The research, involving 7,563 children, provides insights into family circumstances, education, physical health, screen time/online profiles and emotional well-being.
Last year, when they were nine, most of the children were doing well across the various indicators, but the study points to areas of concern, including evidence of significant inequalities.
Researchers found that only 25pc were doing the recommended 60 minutes of physical activity each day.
Although most are not overweight, 22pc are above what is normal for their age, including 5pc who are obese.
Social background plays a big part in overweight and obesity levels, at 32pc in the lowest income group, more than double the 14pc in the highest income families.
They eat more fruit than nine-year-olds did 10 years ago, but there is a relatively high consumption of "treats".
About 12p are hampered by a long-standing health condition or disability, most commonly asthma, ADHD and skin conditions.
These children spent their early years in a period of economic uncertainty, and in 2013, 25pc of families said they struggled to make ends meet.
Generally positive attitudes to school are evident. However, while 62pc of the children "always liked" reading and 48pc "always liked" maths, only 22pc "always liked" Irish.
The study is funded mainly by the Department of Children and Youth Affairs and the research is led by the ESRI and Trinity College Dublin.
Its findings came on the same day as two separate reports provided worrying evidence of the impact that technology is having on young people's health.
A World Cancer Research Fund (WCRF) analysis looked at 80 studies involving more than 200,000 people in order to examine the causes of rising obesity, and identified screen time in childhood as one of the chief culprits.
It follows findings from the WCRF linking being overweight or obese to cancers including breast, prostate, colon, liver, ovarian, kidney and pancreatic.
Elsewhere, research by King's College London found that every hour a day playing computer games raises the risk of short-sightedness, an effect dubbed 'digital myopia'.
In the past 50 years the number of children suffering from myopia has doubled to 16.4pc, which experts say is fuelled by youngsters staying inside and staring at screens.
Previous studies suggest youngsters spend an average of eight hours a day using gadgets like smartphones, desktops and tablets, and scientists warned they appeared to be having multiple effects on their health.
As well as being linked to lower levels of physical activity, it appears to dull satiety levels, leading to 'passive overconsumption' of snacks - often junk foods, which are often marketed via the same devices, the WCRF warned.