Group-living primates maintain reciprocal affiliative relationships with specific group members, yet what cognitive processes generate these relationships is debated. Their affiliative relationships may result from increasingly complex cognitive processes: a) proximity patterns; b) symmetry-based reciprocity; and c) emotional bookkeeping. Agent-based models are an ideal way to explore the link between the cognitive processes employed by an individual and the resulting affiliative relationships. We explored these three cognitive processes in the EMO-model. The EMO-model translates the emotional experience of an affiliative social interaction to a valuation of the relationship with that particular individual (LIKE-attitude). Both symmetry-based reciprocity and emotional bookkeeping result in reciprocal affiliative relationships, yet only emotional bookkeeping generates individual-specific relationships. This indicates that emotional bookkeeping is required for primate-like patterns in affiliative relationships.