124 Ethnic sorting in football The homophily principle These outcomes should be first and foremost interpreted as a reaffirmation of the pervasiveness of the homophily principle. McPherson and colleagues have asserted that homophily should be regarded as a basic organization principle and that voluntary organizations in particular are important foci for homophilic tieformation (McPherson et al., 2001). This dissertation has echoed these assertions by demonstrating the structuring effect of ethnic background on amateur football club membership. When we attribute these outcomes to homophily, we should, however, be careful with solely and directly connecting homophilic tie-formation to deliberate individual decision making. Members do not need to actively compare numbers or percentages of ingroup members for homophily to occur. In fact, some may be completely indifferent to ethnic classifications and still make homophilic choices because other factors such as family, place of residence and social class have produced ethnically homogeneous ego networks which disconnect people from organizations dominated by ethnic outgroup members. Given that tie density is directly associated with membership duration and a substantial share of member recruitment takes place through members’ network ties (McPherson et al., 1992), network homogeneity alone may bring about substantial homophilic tie-formation and tie-dissolution in organized sports. This is not to say that there are no reasons to believe that people prefer contact with members from their own ethnic ingroup and therefore consciously or subconsciously favour and invest their time into memberships of organizations which offer these contact experiences. Social psychologists suggest that ingroup contact can serve important psychological needs like the enhancement of one’s self-image and a reduction of feelings of uncertainty (Hogg, 2000; Tajfel & Turner, 1979). It is important, however, to stress that to the extent that ethnic homophily is the product of a deliberate preference or choice, it is, to reiterate Veldboer et al. (2010), most likely positively motivated. By this, I mean that it is motivated by the importance of sharing experiences with similar others, rather than being motivated by the active disapproval or animosity towards one’s ethnic outgroup(s). Within the field of social psychology these two phenomena, known as ingroup favouritism and outgroup hostility, are considered to be both analytically and empirically distinct (Levin & Sidanius, 1999, pp. 1–2). This also means that, while there is no denying that both implicit and explicit ethnic discrimination in amateur football exists, the results of this dissertation cannot and should not be interpreted as primarily the result of such discriminatory