RESUMO
Pair stability refers to the extent to which exchange occurs between the same actors over time. In a stable pair, actors know what to expect of one another and have a sense of predictability as to the outcome of the exchange. When actors are split into discrete groups, shared group membership contributes to formation of new ties and maintenance of existing ties due to the mechanism of attraction to similar others. Using the formal framework of biased net theory, we propose three hypotheses which link shared group membership with the odds of pair stability. These hypotheses are tested against data from an experiment (N = 180) in which participants were first split into two groups and then given a series of opportunities to share resources with one another. Results of the experiment are consistent with the hypotheses.
