Stimulating Inquisitiveness 5 87 5.1 Introduction In an age of increasing diversity, the importance of enforcing social cohesion in schools is stressed worldwide (Mason & Wareham, 2018; Rissanen & Sai, 2018; Short, 2002). In the Netherlands, for example, it was an important motive for the implementation of citizenship education as a compulsory subject in 2006 (Bron, 2006). Social cohesion can be generally seen as the degree of trust societymembers have in each other and in society itself (Koonce, 2011). When it is about the diversity of people, social capital can be seen as a necessary condition for social cohesion (Koonce, 2011; Putnam, 2007). Social capital consists of both bonding social capital (having “ties to people who are like you in some important way”) and bridging social capital (having “ties to people who are unlike you in some important way”) (Putnam, 2007, p. 143). Both can contribute positively to social cohesion (Koonce, 2011; Putnam, 2007). However, bonding social capital can also have a negative effect when a group’s members isolate themselves from others outside the group (Koonce, 2011). Putnam (2007) concludes that, when it is about diversity in the neighborhood, working toward bridging, as well as bonding, is needed. He points out that more research is needed to see whether the same effects apply to schools and other environments. The current study is on religious socialization, which we define as “the totality of practices, beliefs, ethos and habits of pedagogical agents that may be at the service of children’s (continuing) membership of the religious community” (De Wolff et al., 2003; Homan & Youngman, 1982; Thiessen, 1993; Vermeer, 2010). Religious socialization in religious primary schools can be seen as a form of bonding social capital since these schools aim that pupils connect with the religious community and its faith. However, it is valued differently as to whether or not religious socialization (or teaching into religion; Alii, 2009; Grimmitt, 1981) at schools is an appropriate striving (MacMullen, 2018; Mason, 2018). Positions vary from limiting confession to the private domain and, thus, keeping it away from schools (Cliteur, 2004), to valuing the religious socialization of young children (primary education) under specific pedagogical conditions (MacMullen, 2004, 2018; Merry, 2005, 2013; Short, 2002), and to arguing that education and religious socialization cannot be split (Cooling, 2012; Pike, 2005). Concerns about religious socialization in schools are specifically expressed when it involves strong religious schools because these schools are often associated with promoting intolerance by claiming the tradition’s ultimate truth and with having more or less homogeneous school populations (Jackson, 2004; Mason, 2018; Pike, 2010; Thiessen, 2001; Versteegt & Maussen, 2011). In terms of social capital one could suppose that bonding rather than bridging social capital is emphasized in these schools (Koonce, 2011).