33. THE GENETIC ARCHITECTURE OF VIDEO GAMING BEHAVIOR ACROSS GENERATIONS

Background Play is widespread across species and is thought to support cognitive, motor, and social development. In humans, it also involves imagination, rule-following, and abstract thinking, capacities that enabled the rise of video games. Since the release of the first video game in 1972, gaming has grown into a major cultural and economic phenomenon, with the global industry generating an estimated €186 billion in 2025. Research on gaming and well-being has produced mixed findings. While some studies report links with poorer mental health, larger and methodologically stronger studies suggested positive or effects, including cognitive benefits. Twin studies estimate that around 30% of variation in gaming behavior is explained by genetic factors. Here, we extend this work using genotype data from the UK Biobank and Estonian Biobank. We run genome-wide association analyses (GWAS) and then use the summary level data to perform a range of secondary analyses. By leveraging differences in when video games became culturally available in the UK versus Estonia, we investigate how genetic predispositions interact with the environments. We further examine links of gaming with personality, cognition, and mental and physical health, including potential causal effects of gaming on cognitive performance. Methods We investigated the genetic architecture of video game behavior using GWAS in the UK Biobank (N = 455,482) and Estonian Biobank (N = 81,568). Participants reported gaming frequency or duration. We estimated SNP-based heritability, identified genome-wide significant loci, and meta-analyzed both cohorts. To examine gene–environment interplay, we constructed cross-cohort polygenic scores and tested whether their predictive power differed between individuals who grew up before versus after video games became widely available in each country. We further characterized the genetic signal using phenome-wide association analyses, cross-trait polygenic score prediction, genetic correlations, and Mendelian randomization with IQ and educational attainment. Results Gaming behavior showed modest but significant SNP-based heritability (4–7%), with the meta-analysis identifying 52 independent genome-wide significant loci. Genetic effects were highly consistent across the UK and Estonia despite their distinct historical contexts. Polygenic scores predicted gaming behavior more strongly among individuals who grew up with access to video games, particularly in men, indicating that genetic predispositions are moderated by environmental exposure. Geneic correlations showed positive associations with cognitive traits, openness to experience, BMI, smoking, ADHD, autism, and loneliness, and negative associations with conscientiousness and agreeableness. Mendelian randomization analyses suggested that gaming may have a causal relationship with cognitive performance. Discussion We identified 52 genome-wide significant loci associated with video gaming behavior and found that genetic influences depended partly on historical access to video games. The broad pattern of associations with cognitive, psychiatric, personality, and health-related traits highlights the multidimensional nature of gaming behavior and the importance of environmental context in shaping genetic predispositions.