Crystal Smit

Chapter 6 134 injunctive norms, while in more independent social communities it is effective for lower levels of injunctive norms. This reasoning remains speculative and further research is needed to unravel the role of social norms on the effectiveness of social network interventions in different communities. It is important to recognize that in the pilot study (Chapter 3), the Share H 2 O intervention was effective in increasing water consumption among all children, regardless of social norms. The important role of social norms on the effectiveness of the intervention only emerged in the studies that followed (i.e., Chapter 5 and Franken et al., 2018). One reason for this may be that the general opinion about the importance of drinking water has changed over the years. Over the past five years, the health and environmental benefits of drinking water has drawn much (inter)national attention. For example, national organizations have organized various activities in schools, such as letting children “pimp” their own water bottles (JOGG, 2020) and installing water taps in schoolyards (Gezonde school, 2020). These school activities, combined with mass media attention, may have raised awareness of drinking water among children. It may therefore be that for this group, the content of the Share H 2 O intervention—which mainly focused on the benefits of drinking water—was less new. It would have been interesting if this school and mass media attention for drinking water in combination with the social network intervention had been included as the fourth condition in the RCT in Chapter 5. Changing Perceived Social Norms This dissertation also provided preliminary evidence that social network interventions can change water drinking norms. Chapter 5 showed that the targeted peers reported higher levels of injunctive norms after the Share H 2 O intervention. However, their perceived descriptive norms remained unchanged. A possible reason for this may be related to how the targeted peers perceived the water-promoting strategies applied by the influence agents. In addition to modeling, the influence agents used water-promoting strategies that might have been perceived as pressure by some peers. Strategies such as telling peers they