One psychological theory of relationship maintenance is the investment model. This theory suggests that commitment in a relationship is strengthened by the amount of satisfaction in a relationship which is weakened by presence of possible alternatives. This theory suggests that there should be satisfaction in a relationship in order for it to become long-term. The satisfaction in a product of the outcomes of a relationship. Both partners are only satisfied if they have equal outcomes in the relationship. Another reason, this theory suggests, for a relationship to maintain is the quality if alternatives. If there are not suitable alternatives from the partner that a person is currently with, they will not leave the relationship. Therefore, there must not be an alternative mate for the relationship to not end. As well as this, if both couples have invested a lot of time and effort into their relationship, they are less likely to leave it for an alternative partner. If it is a short relationship where not much has been invested, people are less likely to maintain the relationship. This theory therefore suggests that if a relationship has all strong three categories, they are more likely to commit to a relationship and maintain it. If a relationship does not have all three, they are more likely to break up. A study conducted by Rusbelt and Martz (1995) is a support for this theory. They applied this theory to many cases of abuse. Both researchers went to refuges where women had been abused in a previous relationship and asked them why they didn’t leave as soon as the violence had begun. Like this theory suggests, women felt the greatest commitment to their relationship and partner when their economic alternatives where poor when their investments were great. Like the theory, the findings suggest that if there is a high level of investment and a high level of investment with no alternatives, the women were less likely to leave the relationship. This is a strength because it shows that if the couple is satisfied, has no other alternatives and has invested a lot, they are more likely to commit. In the case to the abused women, they invested a lot into their relationship and they had not other alternatives. Some may argue that this theory is holistic. This means that it considers all the factors which may influence the maintenance of relationships rather than focusing on one point. This theory uses three factors which could influence the maintenance of a relationship. It suggests that if both partners are satisfied, there are no other alternatives and they have invested a lot into the relationship, both partners will be more likely to commit to one another. Despite this, all three do not have to be achieved. As Rusbelt and Martz (1995) found, only two out of the three categories had been achieved. This means that as long as a relationship contains one of them, both people are more likely to commit to the relationship and maintain it. This is a strength of the theory as it acknowledges that every relationship is different which means every couple has a different reason for committing. This theory does not give one explanation but many in order to generalise to every relationship. One psychological theory of relationship breakdown is the Model Of breakdown. This consists of six stages devised by Rollie and Duck (2006). This model focuses on the processes that typify relationship breakdown, rather than being tied to distinct phases that people pass through. Many overlap and will therefore have common features but they are their own distinct stages. The first stage in the relationship starts to breakdown. While the relationship is breaking down, one partner intrapsychically assesses the other partner’s faults as a result of their dissatisfaction within the relationship. This dissatisfaction inevitably leads the person to