What are the psychological impacts of children's screen use? A critical review and meta-analysis of the literature underlying the World Health Organization guidelines

In April 2019, the World Health Organization (WHO) published guidelines on sleep, physical activity, and sedentary behavior for preschool children that included recommendations regarding children's screen time. This article discusses the psychological implications of children's screen-time through a step-by-step, critical review of the literature underlying these recommendations. Out of 33 studies that addressed psychological outcomes of screens, 31 were rated by the WHO as studies with very low-quality and two moderate-quality studies were irrelevant or methodologically problematic. Altogether, the findings did not converge into a unified narrative and many studies produced counterfactual, positive and null results. A meta-analysis of all 33 studies revealed a very small overall effect (r = 0.095) and a significant publication bias (adjusted r = 0.06). These findings corroborate with current literature and suggest that, to date, there is no convincing causal evidence that screen-time (per se) impairs psychological development. Future research is recommended to distinguish between normative and pathological screen use, direct and indirect effects of screens (e.g., through the reduction of healthy daily behaviors), and different screen content (e.g., educational, entertainment, or age-inappropriate content). Future guidelines may emphasize the complexity of the literature and provide parents with more nuanced recommendations regarding children's screen use.