Investment model of commitment

The investment model adds a third factor to interdependence theory, which is investment size. These three factors contribute to a measure of "commitment," which can be used to determine whether or not two people will remain in a relationship with one another. Given that in relationships, there is often an unjustified persistence for people to stay together, it seems as though there must be other things at work besides just satisfaction, and comparison with alternatives. Given this fact, the investment model describes these three factors, and claims that all of these things add up to a central measure of commitment. If commitment, considering all of these factors is high, then the relationship will remain afloat, even if one of the factors is particularly low. In a similar way, if commitment is very low, even if one of the factors is very high, then the relationship will likely end. Investments within this model are characterized into two subsets, intrinsic and extrinsic. Meanwhile, this theory also predicts mechanisms that people employ in order to stay together, who would without investments likely separate. Much has been researched regarding this topic, and evidence points towards the investment model as an accurate predictor of all types of relationship success. == Investment types ==

There are two types of investments defined within the investment model. However, according to Rusbult herself, investment sizes can be modeled by the equation: "Investment Size = the sum total of all investments of a resource multiplied by the importance of that resource." The two types of investments that fit into the total investment size are intrinsic and extrinsic investments, which can include both physical, tangible investments, or intangible ones. Intrinsic investments Intrinsic investments are commonly referred to as things that are put directly into the relationship that we are in. Some tangible examples of this can include spending money on a partner, or giving up possessions for a partner. Meanwhile, intangible examples would include putting in effort to the relationship, or spending quality time. Essentially, intrinsic investments are things that one person has that they use in or on the relationship, usually to make the relationship work. Extrinsic investments Extrinsic investments are things that now exist or have been created because of the relationship. Some tangible examples of this could be the ownership of a house with a partner, or even having children. On the other hand, an intangible example of extrinsic investments would be memories with a partner. Extrinsic investments then are things that have been built up because of the relationship, which would be difficult to lose. == Maintenance mechanisms ==

Rusbult made the claim that relationships that would otherwise separate often tend to stay together, because of the investments they have in the relationship. Because of this, Rusbult explains that partners in these relationships often use various mechanisms to maintain their relationships in the other realms of relationship satisfaction, and comparison with alternatives. The mechanisms used include accommodation, willingness to sacrifice, forgiveness, positive illusions, and ridiculing alternatives. Willingness to sacrifice Willingness to sacrifice is a factor within a relationship that determines how much one partner is willing to give up their interests for the sake of the relationship or for their partner. This sacrifice could be passive or active. Passive sacrifice is when a partner stops doing something, or gives something up, within a relationship. Meanwhile, active sacrifice occurs when a partner starts doing a behavior that they may not want to do, or is not desirable. Many things can affect a partner's willingness to sacrifice, but the primary cause of this behavior is to help maintain a relationship, a direct result of how committed one is to their relationship. Forgiveness Forgiveness is when a partner does something wrong in the relationship, and the other partner decides to not hold a grudge against the partner for that. This can help maintain relationships in many ways. First of all, if a partner does something wrong, leading to lower satisfaction levels, then by forgiving the partner, satisfaction levels could increase, and raise commitment to the partner back up. On top of that, forgiveness has also been found to bolster trust in a relationship, which can predict other factors such as relationship satisfaction and commitment. Positive illusions This method of relationship maintenance typically involves idealizing particular positive traits of one's partner, and minimizing potential negative traits. In this way, partners can think about their partners in a way that is very good, but often objectively better or more idealized that their partners is actually acting. Performing these acts have been linked with higher satisfaction, and trust, which both contribute to commitment towards a relationship, and thus, increase relationship stability and maintenance. Ridiculing alternatives This is a method of relationship maintenance in which partners view any potential alternative partners in a way that makes them seem like worse partners. This can involve thinking less of their positive traits, or attributing negative traits as a larger portion of their personality. Both of these activities are involved in the ridicule of alternatives, and can help maintain ongoing relationships. == Research ==

Impett, Beals, and Peplau (2002) One study, performed by Impett, Beals, and Peplau in 2002, had goals of proving that satisfaction, alternatives, and investments could predict the commitment of married couples, as well as proving that commitment then determined relationship outcomes. In order to test this theory, a longitudinal study was performed in which married participants were mailed a questionnaire to fill out asking various questions about the relationship, regarding satisfaction, investments, and quality of alternatives. Of the couples who participated, 34% were asked to take the questionnaire again 18 months later. After analysis of the data, it was found that levels of satisfaction, quality of alternatives, and investments all fit with Rusbult's predicted model. All of these factors were crucial to building commitment within a relationship. Further, when testing for commitment, it was found that commitment was a strong predictive factor to determine relationship success, over this 18-month period. The study's results displayed that satisfaction tended to be low in these relationships, and that quality of alternatives was usually higher than other, nonabusive relationships. However, many women reported feeling as though they would lose something important, in the form of investments, if they were to leave the relationship. This study showed that all the factors contribute to commitment, and then, that commitment is the deciding factor of relationship success, once again showing strengths of the investment model. This same study also displayed that the investment model continues to describe relationships across cultures and around the world. In both individualistic, as well as collectivist cultures, the investment model is able to predict relationship success using the same factors. Given that many aspects of relationships can be different cross culturally, it shows the predictive power and efficacy of the investment model in predicting human relationships. == Critiques ==

However, there have also been studies which disagree with the investment model's method of prediction. One study, performed by Susan Sprecher, used 197 married couples from Madison, Wisconsin. All of the couples were asked to fill out a questionnaire, with questions about commitment, satisfaction, quality of alternatives, and investments. After answering all of the questions, the results were put together, and it was found that satisfaction and quality of alternatives are much more important for determining total commitment levels than investment size. This disagrees partially with Rusbult's initial model, and supports an interdependence theory way of predicting relationship outcomes, by disregarding the investments. ==References==