This article is an extension to Zeggelink (1994) which introduced the
individual-oriented approach to model the evolution of networks. In th
is approach, the dynamics of friendship network structure are consider
ed as a result of individual choices with regard to friendship relatio
nships. Individuals have specific characteristics and behavioral rules
. The previous model was based solely on individuals' different needs
for social contact. In the model presented here, we introduce another
important determinant of friendship formation: preferences for similar
friends. The amount of heterogeneity of the distribution of individua
l characteristics on which this similarity is based thus becomes impor
tant. In contrast to most existing dynamic social network models, this
aspect of heterogeneity, as well as dependence of dyads, can easily b
e dealt with. We examine how individual characteristics and preference
s (individual attributes at the micro level) with respect to prospecti
ve friendship relations interact and aggregate to outcomes at the macr
o level: the network structure.