Maartje Boer

CHAPTER 1 16 and furthermore, to compare their country-specific findings with research on problematic SMU in other national contexts. Additionally, validating a problematic SMU-scale cross-nationally provides global knowledge about the phenomenon, namely about the prevalence as well as the extent to which it is indicative of adolescent health risks worldwide. Are There Cross-National Differences in the Extent to Which SMU Intensity and SMU Problems Are Related to Wellbeing? Up till now, studies on the association between SMU and wellbeing typically have used single-country data. As a consequence, we do not know whether the earlier found associations are country-specific or emerge across countries. That is, it remains unclear whether the association depends upon the national context in which adolescents grow up in. Research suggests that once risk behaviors, such as substance use, become accepted within a society, these behaviors become normalized (Haskuka et al., 2018; Sznitman et al., 2015). As a result, these risk behaviors are not indicative (anymore) for adolescents with problematic profiles, but instead, may represent well-adjusted adolescents (Sznitman et al., 2015). In a similar vein, when many adolescents show high levels of SMU intensity and/or SMU problems within a society, these behaviors may not or to a lesser extent be indicative of lower wellbeingwithin that society. Theories on the effects of (social) media use often explain the effect while disregarding the wider contexts adolescents are in. Therefore, identifying in which national contexts particular SMU behaviors increase the risk of lower wellbeing advances current theory on social media effects. In doing so, to improve our understanding of SMU effects, it is important to highlight the differences between SMU intensity and SMU problems in how they relate to wellbeing. Furthermore, wellbeing is a broad concept that encompasses many facets. Given that SMU behaviors may be more strongly associated with some domains of wellbeing than others (Richards et al., 2015), it is essential to distinguish between multiple domains of wellbeing, such as adolescents’ mental health, social wellbeing, and school wellbeing. Establishing in which national contexts high SMU intensity and SMU problems increase the risk of poorer wellbeing identifies in which national settings the implementation of intervention programs aimed at supporting adolescents with particular SMU behaviors could be most valuable.