Research has demonstrated the importance of comparison levels in relationships. Simpson et al. found that participants in existing relationships rated people the opposite gender as less attractive than participants not in relationships. This suggests that people judge prospects of new alternative relationships as less profitable if they are already in a committed relationship.
In addition, the comparison level for alternatives may provide an explanation as to why many women choose to stay in abusive relationships. If investments in the relationship are high like children and financial security and the alternative prospects are bleak like homelessness, then a woman may see staying in the abusive relationship to be more profitable than leaving it.
However, there has been a lot of conflicting research. Studies by Argyle have shown that both rewards and costs involved generally increase as a relationship develops. Relationship closeness involved rewards plus costs not rewards minus costs like the theory suggests.
Further research by Argyle argue that people only really begin to count the costs and monitor the relationship after they have become dissatisfied.
Similarly, Duck argues that people do not keep an eye on other alternatives which are on offer and only start to consider alternatives when they become dissatisfied with their current relationship.
An alternative theory is the equity theory. Equity theory devised by Walster proposes that people strive to achieve fairness in their relationships, any inequity can cause distress. Relationship satisfaction is highest when each partner feels that they give the same amount into the relationship and get the same amount of rewards from it. Inequity, when people feel that they are giving a lot & getting little out of the relationships or are giving little and getting a lot, leads to dissatisfaction & distress.
There is research evidence which suggests that equitable relationships are the most satisfactory ones. Stafford & Canary found marital satisfaction to be lowest in people who considered themselves to be under-benefited and highest in those who felt they were in equitable relationships. This supports equity theory, which proposes that equity in a relationships leads to satisfaction.
Research supports that people are more satisfied in equitable relationships than in profitable ones, but men and women to judge equity differently. Steil and Weltman found that in couples where the husband earns more, both partners view the husband’s work as more important. This was not reversed when the woman earned more. This tendency for women to seek less for themselves in a relationship makes equity difficult to judge.
However, Clark & Mills disagreed with this idea that all relationships are based on economics as they felt that exchange relationships like between colleagues are very different to romantic relationships. They argued that relationships are driven by a desire to respond to the needs of the partner, not to keep track of rewards & costs.
Overall, both theories are reductionistic. The SET only focusses on the individual’s view of their relationships, ignoring any relevant social aspects. And the equity theory and SET suggests that the relationship must be fair in order for it to be maintained but, this isn’t the case as some people will be in unrewarding, unfair relationships, like abusive relationships. This means there must be other factors that contribute to the maintenance of relationships.
Also The theories has been criticised by psychologists for being deterministic by ignoring the role of free will of individuals by suggesting that we only take into account the fairness, rewards and costs and ignores our individual choices or other factors. Therefore it’s unlikely to explain the explanation into the maintenance of all romantic relationships and thus reducing the external reliability of the theories.
Furthermore, they show imposed etic. They assume all cultures however we know this isn’t the case. In eastern cultures where arranged marriages are common they do not focus on costs, rewards and fairness. These theories fail to explain all of relationships.
Lastly, the theories of maintenance into romantic relationships do not explain the maintenance of homosexual relationships, as homosexuals do not engage in traditional roles i.e. man and wife, and therefore the costs and rewards for them may be different and therefore doesn’t explain maintenance as a whole.
In conclusion, these theories provide useful explanations to maintenance of aggression but they fail to consider all cultures and relationships and cannot explain relationship maintenance as a whole.