Adolescents who exhibit problematic smartphone use tend to reallocate their daily hours away from studying and toward screen-based entertainment, which ultimately hinders their ability to manage their own learning. While heavy smartphone use also goes hand in hand with heightened academic stress, this stress appears to be a pre-existing condition rather than a direct consequence of digital habits. The research was published in Behavioral Sciences. As smartphones have become central to modern life, psychologists have debated how excessive use impacts adolescent development. Past research has consistently linked problematic smartphone use to depression, anxiety, and poorer school performance. Problematic use refers to a pattern of overdependence that interferes with daily life, rather than a clinical addiction diagnosis. Despite these known associations, the specific ways in which screen habits alter teen development remain a subject of active debate. Joungmin Kim, a researcher at Soonchunhyang University in South Korea, designed the current study to test two complementary ideas regarding how digital habits influence growing teenagers. The first idea is a stress-activation theory. This proposes that excessive smartphone use …