Short, Animated Storytelling (SAS) Videos to Reduce Smartphone Addiction in the US

SmAS is a short 10 item validated scale measuring smartphone addiction. The minimum value is 10 and the maximum value is 60 for this scale.

The MPAS Anxious Attachment subscale comprises 7 items rated 1 (not at all true) to 5 (extremely true). Subscale scores were computed as the mean of the 7 items (range 1-5), with higher scores indicating greater anxious attachment to one's mobile phone. The MPAS-AA has demonstrated good internal consistency (α=.87) and external validity.

Mobile phone addiction will be assessed with the MPAS Addiction subscale (6 items). Items are rated on a 5-point scale from 1 = not at all true to 5 = extremely true; responses are averaged to create a subscale score (range 1-5), with higher scores indicating greater addictive/problematic mobile phone use.

Perceived danger of smartphone overuse will be assessed with a single-item 10-point slider (visual analogue-type scale) ranging from 0 = not at all dangerous to 10 = extremely dangerous. Higher scores indicate greater perceived danger.

Self-reported daily smartphone use will be assessed via a single self-report item asking participants: 'On average, how many hours per day did you use your phone over the past two weeks?' Responses are recorded in 6 ordered categories: <1 h, 1-2 h, 2-4 h, 4-6 h, 6-8 h, >8 h, with higher categories indicating greater daily use.

Self-perceived smartphone addiction will be assessed using Olsen's single-item smartphone addiction measure, asking agreement with the statement 'I am addicted to my smartphone' on a 6-point Likert scale from Strongly disagree (1) to Strongly agree (6). Higher scores indicate greater self-perceived smartphone addiction.