An exploration of the impact of smartphones in childhood on mind health in young adulthood

As digital technologies become increasingly embedded in childhood, understanding their long-term effects on mental functioning is of critical importance. This working paper draws on data from over 130,000 individuals aged 18 to 24 across 59 countries, as part of the Global Mind Project, to explore the association between age of first smartphone ownership and mind health in early adulthood. Using the Mind Health Quotient (MHQ), a multidimensional and functionally grounded assessment of mind health and wellbeing, the study finds that younger age of smartphone acquisition is strongly associated with diminished capacities and increased psychological distress in early adulthood. Individuals who received smartphones each year before the age of 13 show higher levels of suicidal thoughts, aggression, and hallucinations, along with reduced emotional resilience and self-image resulting in an increase of 10% who are clinically distressed or struggling between those who got a phone below age 10 vs above age 13. These effects are more pronounced among females and are consistent across global regions. The analysis also examines lifestyle and interpersonal factors that may mediate this relationship, including age of first social media use, sleep sufficiency, diet, family closeness, friendships, and exposure to trauma. Regression models suggest that these factors together explain approximately 56% of the observed association, with age of social media account, sleep, and family relationships contributing most significantly. The findings point to a cumulative developmental impact of early smartphone exposure on mental functioning and highlight the need for early interventions, including policy measures to delay smartphone and social media access.