Have you ever heard an unhappy couple say that they will stay together for the kids? The costs of their relationship greatly outweigh the benefits, but they stay together because they have had children and are now heavily invested. Rusbult’s investment model of commitment explores how three different aspects affect the stability of a relationship over time, highlighting the role of commitment and how it varies.
- First, we will look at Rusbult's investment model of relationships.
- Then we will explore this further by looking at Rusbult's investment model in terms of commitment.
- After, we will distinguish between Rusbult's investment model and social exchange theory.
- Next, we will go over research for investment model examples.
- Finally, we will discuss an evaluation of Rusbult's investment model.
Fig. 1 - Rusbult's investment model explores commitment in relationships.
Rusbult's Investment Model of Relationships
Rusbult et al.'s (2001) investment model is an extension of social exchange theory, which suggests that people in relationships constantly analyse the cost and benefits of a relationship. Rusbult explores how satisfaction, comparisons with alternatives and investment levels affect commitment rather than focusing on the cost and benefit analysis in social exchange theory.
The most critical factor of Rusbult’s (1980, 1983) theory is people's investment in relationships, affecting commitment and the stability of a relationship.
Investment refers to both tangible and intangible assets in a relationship. Tangible investments are quantifiable, physical investments such as money and children, whereas intangible or immaterial investments could refer to happy memories.
According to Rusbult (1980):
Commitment to a relationship is said to be a function not only of the relationship outcome value, but also the quality of the best available alternative and the magnitude of the individual’s investment in the relationship (p. 172)
Rusbult also divided investments into intrinsic and extrinsic categories. The intrinsic category refers to things we put directly into a relationship, such as money and time. In contrast, extrinsic investments result from relationships and are formed due to the association with current behaviours in relationships, such as happy memories and shared friends.
Rusbult stated that the bigger the investment, the more likely the couple will stay together.
Rusbult's Investment Model of Commitment
According to Rusbult (1980, 1983), couples maintain levels of commitment in relationships for three reasons:
Satisfaction: How well the relationship satisfies the person's needs and wants.
Comparison with alternatives: How other relationships compare to the current one, and how well they could fulfil needs in comparison (especially if the current one does not fulfil needs well).
Investment size: How much a person has put into a relationship overall.
Fig. 2 - Couples commit to the relationships due to satisfaction, comparison and investment.
These reasons link to commitment and stability in relationships.
| Factors | Combined Result |
| Satisfaction. | Commitment and stability. |
| Comparison with alternatives. |
| Investment levels. |
How can we distinguish between Rusbult's Investment Model and Social Exchange Theory?
Rusbult's investment model is an extension of social exchange theory, which suggests that people in relationships are constantly undergoing an analysis of the cost and benefits of them being in that relationship, including their level of investment (time, effort. money etc.) and comparison to other past or potential partners.
Rusbult explores how satisfaction, comparisons with alternatives and investment levels affect commitment, rather than focusing on the cost and benefit analysis in social exchange theory. Social exchange theory concentrates more on how people seek to minimise costs and maximise rewards.
Investment Model Examples: Research
There are a few prominent studies concerning Rusbult’s Investment Model as examples of real-world application of relationship investment models.
Le and Agnew (2003)
Le and Agnew (2003) conducted a meta-analysis of 52 studies with 11,582 total participants and discovered that satisfaction, comparison with alternatives, and investment greatly contributed to commitment.
Commitment levels were significantly associated and predicted whether someone would remain in the relationship overall.
Impett, Beals, and Peplau (2002)
Over 18 months, Impett, Beals, and Peplau (2002) conducted a longitudinal study of 3,627 married couples (husbands aged 17 to 79 years and wives aged 17 to 77 years).
They found that there was a strong correlation between stability and commitment. Spouse satisfaction, the investment they put into the relationship, and potential alternatives were predictors of their levels of commitment to the relationship.
Multi-group path analyses indicated that Rusbult's investment model coincided quite well with the data, suggesting that the model has evidence-based research backing it.
Fig. 3 - Spouse satisfaction is an important factor in a committed relationship.
Rhatigan and Axsom (2006)
Rhatigan and Axsom (2006) studied a group of shelter-based battered women and their reasons for staying with their partners. They were interested in why they decided to stay committed to abusive relationships and investigated it using the parameters set out by Rusbult's investment model.
They found that all three of Rusbult’s factors (satisfaction, comparison with alternatives, and investment) contributed uniquely to part of the women’s decision to stay with their partners and that this relationship satisfaction helped mediate the relationship between psychological (but not physical) abuse and commitment.
Bui, Peplau, and Hill (1996)
Using multiple regression analyses, Bui, Peplau, and Hill (1996) studied 167 heterosexual couples over 15 years (1972-1987).
They found that rewards and costs greatly influenced satisfaction, whilst the availability of alternatives, investment, and satisfaction influenced commitment, supporting Rusbult’s theory. Again, they found that Rusbult's model fits quite well with the data (using path analyses), and associations were similar for men and women.
Rusbult's model predicted the relationship duration in the study.
Evaluation of Rusbult's Investment Model
Understanding the weaknesses and strengths of Rusbult’s investment model is important. Like all theories on human behaviour, we must establish how robust the knowledge behind the theory is.
Weaknesses
Weaknesses include correlational research and reductionism.
- Rusbult’s investment model suggests that investment equals commitment. However, this is a correlation as we cannot accurately predict or quantify investment since it differs from person to person. The model cannot prove causation.
- Goodfriend and Agnew (2008) argued that there are few empirical analyses of investments and their predictive power of state or fate of relationships. They suggested that the investment model is oversimplified. Partners may stay in a relationship to see plans realised despite not ‘investing’ in such plans in the present moment.
For instance, someone may stay with their partner to have kids with them. This future investment motivates their relationship, but the investment model fails to acknowledge this.
Strengths
Strengths include research support, self-report techniques, and an explanation for staying in abusive relationships. They also include cross-cultural applications and enrichment of social exchange theory.
- As we have seen, research from Le and Agnew (2003), Bui, Peplau, & Hill (1996), Rhatigan and Axsom (2006), and Impett, Beals, and Peplau (2002) support Rusbult’s model.
- Although self-report techniques in studies of Rusbult’s model have real-world validity and applications, the nature of this data collection is that they are subjective but unreliable. Therefore, whilst Rusbult’s model is not remarkably scientific, it has many real-world applications.
- Rusbult’s investment model explains why someone would stay in an abusive relationship, showing that it has real-world validity. If someone has invested much in their relationships, such as time, money, or children, they may stay despite the present costs outweighing the benefits.
Research from Rusbult and Maltz supports this explanation. When studying 100 female abuse victims, they found they were more likely to return to their abusive relationship if they felt they had invested a lot into it. This finding shows the real-world applications of the investment model.
- Le and Agnew (2003) found in a meta-analysis of 52 studies that the investment model is valid in individualist and collectivist cultures. Associations between commitment and bases vary minimally depending on demographic factors (such as ethnicity). It has also been proven to explain commitment in different cultural subgroups, such as the LGBTQIA+ community.
- The investment model explains why people stay in relationships despite unbalanced rewards and costs, which social exchange theory fails to do.
Rusbult’s Investment Model - Key takeaways
Rusbult investment model, developed in 1980, explains why people commit to relationships, exploring how certain factors affect the development and stability of relationships.
Rusbult highlighted three factors that affect the commitment and stability of relationships: satisfaction, comparison with alternatives, and investment size.
He stated that people invest intangible and tangible resources and intrinsic and extrinsic investments in relationships. The more significant the investment, the more likely a couple will stay together.
Research from Le and Agnew (2003), Bui, Peplau, and Hill (1996), Rhatigan and Axsom (2006), and Impett, Beals, and Peplau (2002) support Rusbult’s model. The investment model explains why people stay in abusive relationships.
However, issues with the model exist in that it can only provide correlational evidence, and research suggests it is oversimplified.
References
- Rusbult, C. E. (1980). Commitment and satisfaction in romantic associations: A test of the investment model. Journal of experimental social psychology, 16(2), 172-186.
- Impett, E. A., Beals, K. P., & Peplau, L. A. (2001). Testing the investment model of relationship commitment and stability in a longitudinal study of married couples. Current Psychology, 20(4), 312–326. https://doi.org/10.1007/s12144-001-1014-3
- Rhatigan, D. L., Street, A. E., & Axsom, D. K. (2006). A critical review of theories to explain violent relationship termination: Implications for research and intervention. Clinical psychology review, 26(3), 321-345.
- Bui, K. V. T., Peplau, L. A., & Hill, C. T. (1996). Testing the Rusbult model of relationship commitment and stability in a 15-year study of heterosexual couples. Personality and Social Psychology Bulletin, 22(12), 1244-1257.
- Goodfriend, W., & Agnew, C. R. (2008). Sunken costs and desired plans: Examining different types of investments in close relationships. Personality and social psychology Bulletin, 34(12), 1639-1652.
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