Crystal Smit

Chapter 6 138 relatedness) are facilitated (Ryan & Deci, 2000). Future research could measure these self-determination theory-related psychological mediators (namely, autonomy, competence, and relatedness) to gain more insight into how to optimally promote intrinsic motivation (Vlachopoulos & Michailidou, 2006). This could provide guidance for water promotion intervention developers in choosing and applying self-determination theory-related motivational strategies (Gillison et al., 2019; Teixeira et al., 2020). IMPLICATIONS FOR RESEARCH AND INTERVEN- TION PRACTICE The Motivation of Children Chapter 3 indicated, in line with other literature, that intrinsic motivation plays an important role in predicting long-term changes in health behaviors (e.g., Mata et al., 2009; Pelletier et al., 2004; Ryan et al., 2008; Silva et al., 2011; Teixeira et al., 2015). We therefore recommend social network intervention developers, in addition to the influence agents, to focus on enhancing the intrinsic motivation of the target children. This could be achieved by teaching the influence agents, through role-play for example, to use autonomy-supportive water-promoting techniques that reinforce the intrinsic motivation of their peers (Sebire, Edwards, et al., 2016). However, this would mean that the influence agents training would become longer and more intensive, because in addition to practicing through role-playing, they would also need to learn the core idea behind being autonomy supportive. Another possibility, and probably less time consuming, would be to prompt the influence agents after a certain period of time to actively promote the behavior among their peers again. Research on the application of habit formation for health behavioral change has shown that through repetition a habit (in this case drinking more water) can gradually become a routine (Gardner & Rebar, 2019; Lally & Gardner, 2013). However, future research should investigate whether this possibility could lead to long-term effects for social network interventions.