A multifaceted nudge-based intervention to reduce smartphone use: Findings from a randomized cross-over trial

The widespread use of smartphones has raised concerns about problematic usage behaviors, including excessive screentime and frequent phone checking, which can disrupt daily functioning. This study aimed to evaluate the effectiveness of a multifaceted nudge-based intervention in reducing smartphone use through subtle changes to smartphone settings. The intervention incorporated adjustments such as disabling face/touch ID, setting longer passwords, switching to grayscale mode, and removing social media apps from the home screen. A randomized within-subject cross-over trial with counterbalancing was conducted over a two-week period using a daily diary approach paired with objective smartphone usage data to track the impact of these interventions on both smartphone screentime and checking behavior. Multilevel modeling on 163 young adults with 1508 observations indicated that the intervention significantly reduced both screentime and checking frequency compared to the control condition. However, participants reported higher levels of stress during the intervention, potentially due to the frustration of partial restrictions without full disengagement from their smartphones. These findings highlight not only the potential of multifaceted nudges to reduce smartphone use but also the importance of carefully selecting and combining strategies to avoid unintended stress. This study provides a practical, cost-free and scalable foundation for refining smartphone interventions, contributing to the growing body of research on nudge-based strategies to promote healthier phone habits.