When an interdependent relationship is in its early stages, what’s often referred to as the “honeymoon phase,” each side is likely to go out of their way to please the other or even tolerate something that they would normally find annoying.
Gradually, this period can fade, and before making any commitments, each person may start to rationally analyze their interactions.
More specifically, they weigh the pros—their perceived positive values or rewards, like feeling loved, having a companion, and enjoying adventurous vacations together—and the cons—perceived negative attributes or costs, like infrequent communication and never completing chores—to drive an outcome, such as deciding to stay in the relationship.
This type of cost-benefit analysis buys into the framework of Social Exchange Theory—the notion that social behaviors are part of an exchange process, whereby people are motivated to increase their benefits and decrease costs.
Here, the girl is more likely to stay in the relationship with her partner if she is able to identify more positive features than negative ones: that is, in the overall worth, the rewards outweigh the costs.
In any case, the standards that people use for evaluating social situations may also vary with time and from person to person. For instance, her expectations of the rewards and costs in her current and future relationships may be based on previous experiences, such as an ex-partner who always spoiled her with gifts and expensive dinners.
Thus, prior relationships that were high in rewards may set up high expectations in the future and vice versa.
In this state of comparison, she may also analyze possible alternatives. Perhaps the current relationship is better than anything else out there. If that’s the case, then she may reassess and decide to continue the current relationship.
In the end, Social Exchange Theory is one of the key theories about what drives people’s satisfaction with their relationships and ultimately their choice to maintain or leave a relationship.