The aim of this study is to identify the central and peripheral actors in two ethnically homogenous theoretical high school classes, in order to prove that the positive and the negative ties produce different networks. Measures of density and centrality were used for identifying differences between the two types of social networks. The results confirmed that, at the network level, the negative network is not the inverse of the positive network. At the individual level, results did not indicate whether those persons who are on the periphery of the positive network are also on the periphery of the negative network. Furthermore, besides confirming the fact that the positive networks are denser than the negative ones, I found that negative networks are highly polarized in comparison with positive networks.