Effects of screen time on preschool health and development – Research report

New Zealand children have unprecedented access to personal screen based devices such as phones, gaming devices and tablets for educational and entertainment purposes. International research also shows excessive use of screen-based devices can increase the likelihood of several health and behavioural outcomes.

The Effects of screen time on preschool health and development study is the first to look at children’s screen time usage based on New Zealand-only data. Screen-time data was analysed for more than 5,000 pre-schoolers from the Growing Up in New Zealand study, New Zealand’s largest longitudinal study of child development.

The researchers set out to understand trends in the duration and type of screen usage at 24 months (2 years of age), 45 months (3.75 years of age) and 54 months (4.5 years of age). They also sought to determine the association between screen usage at 2 years of age and a range of physical, behavioural and social outcomes at 4 years of age.

The research was conducted in association with the Ministry of Health. In 2017, the Ministry of Health released national screen time guidelines for under-fives (download Active Play Guidelines, 2017, pdf 832 KB).

The Ministry of Social Development funds Growing Up in New Zealand and administers and funds the Children and Families Research Fund, which funded this research. Through the research fund, $750,000 is made available each year for policy-relevant research projects using Growing Up in New Zealand data.


  • Time spent on screens tends to increase as preschool children age, with the largest increases seen with portable electronic media (ie computers, tablets, smart phones and gaming devices). The average time preschool children spent using screens is about 1.5 hours each day at 2 years of age, which increased to two hours per day when children were 3.75 years of age. The Ministry of Health guidelines for screen time usage is less than one hour each day for children aged 2 to 5 years.
  • NZ European ethnicity, lower socioeconomic deprivation, enforcing household screen time rules and fewer televisions in the household were consistently associated with meeting the screen time guidelines at each time point.
  • Children who exceeded the one hour per day screen time guideline at 2 years are more likely to be obese, have more illnesses and visits to the doctor, have lower physical motor skills, and may exhibit hyperactivity problems at 4.5 years of age.
  • The findings provide the first evidence that adherence to current Ministry of Health screen time guidelines is linked to better health outcomes in New Zealand children.

The views and interpretations in funded research reports are those of the researcher(s) and are not the official position of the Ministry of Social Development.

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