A Genetically Informed Study of Digital screen time, Video game play, and Impulsivity in Established Adulthood.

High levels of digital screen time are associated with heightened impulsivity, though the assumption that this relationship is causal has seldom been rigorously examined. Moreover, the nature of this association may vary across life stages. Adults in established adulthood (ages 30-45) often face increased career and family commitments, which may impact leisure activities and the relationship between screen time and impulsivity. This study examined the association between digital screen time, video game play, and facets of impulsivity (i.e., perseverance, premeditation, and urgency) in adults in established adulthood using a multi-method approach, including a genetically-informed co-twin design. By comparing within-twin pair differences in screen time and impulsivity, the co-twin approach controls for genetic and environmental confounding, providing a quasi-experimental design. The sample included 1,289 participants ( = 33.46, %Female = 52.75%, = 704) from the Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging (CATSLife). After controlling for adolescent impulsivity, phenotypic analysis found that digital screen time was positively associated with higher levels of urgency and lack of perseverance. Co-twin control analysis showed that the association between digital screen time and urgency persisted within twin pairs, suggesting that shared familial and genetic factors may not fully explain the relationship. Video game play did not show consistent associations with impulsivity. These findings suggest that the immediacy and rapid succession of stimuli in digital screen engagement could be associated with impulsive tendencies in established adulthood, independent of video game play. The study underscores the need for nuanced examination to understand the interplay between digital engagement and impulsivity in this unique life stage.