Intimate Relationships and Commitment

Social psychologists are interested in determining which factors help partners stay committed to one another. Intimate relationships progress when two people come together and are fully committed to making their relationship work. Commitment is defined as and individual’s intent to maintain the relationship and to remain psychologically attached to it. The individual wants to sustain a relationship with their partner over time. 

Satisfaction level “refers to positive versus negative affect experienced in a relationship” (Rusbult, Martz, Agnew, 1998). A person whose needs are met by his or her partner will enjoy a higher level of satisfaction. Quality of alternatives is defined as the attractiveness of the best obtainable alternative to a relationship (Rusbult et .al, 1988). For example if someone's need for intimacy could be met elsewhere, their quality of alternatives would be high. Investment size is the amount and significance of the resources that are attached to a relationship, and if the relationship were to end the resources would decline in value (Rusbult et. al, 1988). Resources of investment can be family such as mutual friends and time or shared material possessions such as a house and cars. Rusbult also found two variables which were linked to commitment. The first variable is equity, the ability to be fair. Equity in a relationship is highly important because inequity, or being unfair, causes distress. Rusbult’s proposition suggests a partner in a inequitable relationship would be less committed to the relationship and want to omit the distress, ending the relationship. The second variable is social support such as family and friends. This variable is external. If family and friends commend the relationship it produces a positive influence causing the couple to stay together longer.

Three studies utilizing various methods calculated the consistency and strength of the Investment Model Scale. The studies administered scales to a sample of individuals who were involved in ongoing romantic relationships utilizing items that have been exploited in previous research on the investment model. In the first study she managed scale items to a sample of individuals who were involved in ongoing romantic relationships, utilizing items that have been exploited in previous research on the Investment Model (Rusbult et. al, 1988). The second study was modified based on the results of the first, (Rusbult et. al, 1988). The third study Rusbult made alterations to the previous ones and followed up with a telephone interview. The scale is intended to measure commitment level, satisfaction level, quality of alternatives, and investment size. The Model of Investment Scale revealed good consistency to measure each process, satisfaction level, quality of alternatives, and investment model.

Rusbult also conducted another study to support her findings of determinants for relationship commitment using the Investment Model. Her research complies with her prediction. “According to the investment model, satisfaction with a relationship should be greater to the extent that a relationship provides high rewards and low costs, whereas commitment increases not only due to greater relationship satisfaction but also to increases in the investment of resources in relationships and declines in the quality if available alternative partners”(Rusbult, 1980). Satisfaction and quality of alternatives drive the commitment in a relationship with high rewards and low costs. Susan Sprecher also conducted a study which supports Rusbult's findings. Sprecher (1988) found all of the predicting variables except investments were related to relationship commitment.