Crystal Smit

Chapter 2 28 intervention approaches (Cruwys et al., 2015). In addition, there is a need for intervention research taking into account the social status of the peers, given that the modeling effect may be stronger for role models who have a specific status in class (Teunissen et al., 2012). Therefore, the present study aims to promote water drinking by incorporating the social modeling mechanism in conjunction with peer status among children. A theory that integrates both social influence and social network status is Roger’s diffusion of innovation theory. It explains how members of a social network model the behavior and ideas of others (Rogers, 1962, 2010). High status peers or influence agents are individuals who have the most influence during the diffusion process due to their unique position in their social network, such as having a higher social status and more influence as a change agent (Rogers, 2010). Moreover, the ones who serve as role models in their social network are often most popular, well- liked, and trusted by others (Kelly, 2004; Valente & Pumpuang, 2008). The use of influence agents has already been applied successfully in the field of public health aimed at preventing HIV (Kelly et al., 1991) and decreasing tobacco use (Campbell et al., 2008; Valente et al., 2003). In these interventions, the most influential peers were identified and trained to spread and sustain new norms of behavior within their social networks. In the current pilot study, we also followed this social network approach and trained the influential peers to promote water consumption within their social networks. Children do not drink enough water and apparently this beverage is considered unpopular among this age group (Drewnowski et al., 2013). Therefore, the training of the influence agents itself was developed based on insights from two important social influence theories: self-determination theory (Deci & Ryan, 1985) and self- persuasion theory (Aronson, 1999). According to the self-determination theory, supporting individuals’ need for autonomy, relatedness, and competence (e.g., by providing choices) leads to autonomous internalization of behaviors that were initially of extrinsic origin (Deci & Ryan, 1985; Soenens & Vansteenkiste, 2010). Based on this, the training was designed to support the autonomy of the influence