Almost a quarter of Irish 9 year olds have a social media or online gaming profile.
Boys' related to computer games, while for girls it was for apps like Snapchat and Instagram, despite being too young to sign up.
The latest Growing Up in Ireland study which is tracking over 7 and a half thousand children and their families also found that 22 per cent of 9 year olds are overweight or obese.
Only one-quarter of 9-year-olds reached the recommended level of physical activity - that's at least 60 minutes every day.
15% of all 9 year olds spent 2 or more hours watching TV or DVDs on weekdays.
Meanwhile the children generally had positive attitudes to school - 62% said they always liked Reading; 48% always liked Maths but only 22% always liked Irish.