  We present a simple model for the formation of pairs in multi-agent
populations of type A and B which move freely on a spatial network. Each agent
of population A (and B) is labeled as Ai (and Bj) with i=1,.. NA (and j=1,..NB)
and carries its own individual list of characteristics or 'phenotype'. When
agents from opposite populations encounter one another on the network, they can
form a relationship if not already engaged in one. The length of time for which
any given pair stays together depends on the compatibility of the two
constituent agents. Possible applications include the human dating scenario,
and the commercial domain where two types of businesses A and B have members of
each type looking for a business partner, i.e. Ai+Bj-->Rij. The pair Rij then
survives for some finite time before dissociating Rij-->Ai+Bj. There are many
possible generalizations of this basic setup. Here we content ourselves with
some initial numerical results for the simplest of network topologies, together
with some accompanying analytic analysis.
