The cost-benefit ratio is the ratio of the efforts that have to be made to establish and/or maintain a relationship (costs) to the rewards that will amount as a result (benefits).  A person considers the history of rewards received during an interaction with another person and weighs that against the history of costs; an estimate is then made determining the worth of the relationship.  Thus, when the rewards outweigh the costs, the relationship will most likely be continued; yet if the relationship is deemed too costly, it most likely will not be pursued (LeFleur, 2005).

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