Theories of RR: Rusbult’s investment model

• Investment model:

  • Rusbult’s Investment Model is a development of Social Exchange Theory (so you’ll be familiar with some of the concepts we will look at)
  • According to Rusbult et al. (2011), commitment to a relationship depends on three factors:
  • Satisfaction level
  • Comparison with alternatives
  • Investment size
• Satisfaction and comparison with alternatives:

  • Rusbult’s model suggests that satisfaction and CLalt are two factors that affect commitment
  • Satisfaction is based on the concept of comparison level (CL) and comparison with alternatives (CLalt)
  • Each partner is generally satisfied if they are getting more rewards out of the relationship than they expect based on previous experience and social norms.
  • Satisfaction is also based on whether a partner believes they can gain more rewards from alternative partners or whether all of their reward needs are satisfied by their current partner
• Satisfaction and comparison with alternatives:

  • No interest in alternatives satisfaction commitment 
  • However, satisfaction/dissatisfaction alone is not enough to mean a person leaves/stays in a relationship.
  • It is COMMITMENT which is the most important factor.
• Rusbult’s Development of Social Exchange Theory

  • Rusbult realised that the CL and CLalt derived from the SET are not enough to explain commitment
  • If they were, then many more relationships would end as soon as either:
  • Costs outweighed rewards (loss)
  • More attractive alternatives presented themselves
  • Therefore, Rusbult introduced a crucial third factor influencing commitment: INVESTMENT
• Investment size:

  • Investment can be understood as anything we would lose if the relationship were to end
  • Rusbult argues that there are two major types of investment:
  • Intrinsic investments are any resources we put directly into the relationship. E.g. Money, possessions, energy, emotions, self-disclosure, etc.
  • Extrinsic investments are resources that previously did not feature in the relationship but are now closely associated with it. E.g. Possessions bought together, mutual friends, children.
• Satisfaction vs Commitment

  • Rusbult argues that the main psychological factor that causes people to stay in romantic relationships is commitment – NOT SATISFACTION. What’s the difference?
  • A partner may not be unhappy and unsatisfied in their relationship
  • But they may feel committed because they have made an investment that they do not want to see go to waste
  • Therefore, even though they are not satisfied they still work hard to maintain and repair a damaged relationship
• According to the model, long-lasting partners show their commitment by engaging in the following maintenance mechanisms:

  • They will act to promote the relationship (accommodation)
  • They will also put the partner’s interests first (willingness to sacrifice) 
  • They will forgive them (forgiveness)
  • They are unrealistically positive about their partner (positive illusions)
  • They are negative about tempting alternatives and other people’s relationships (ridiculing alternatives)
• AO3:

  • A strength of Rusbalt’s investment model is that there is cross-cultural research to support it
  • Le and Agnew (2003) reviewed 52 studies including 11,000 male and female participants, from 5 countries, in heterosexual and homosexual relationships 
  • They found that satisfaction, comparison with alternatives and investment size all predicted relationship commitment
  • This suggests that there is some validity to Rusbult’s claim that these factors are universally important features of romantic relationships
• AO3:

  • strength of Rusbult’s investment model is that it is a particularly valid and useful explanation of relationships involving intimate partner violence
  • Rusbult and Martz (1995) studied women who had been physically abused at a shelter 
  • They found that those most likely to return to an abusive partner reported making the greatest investment and having the fewest attractive alternatives
  • This is consistent with Rusbult’s model which suggests that investment and comparison to alternatives determines how committed someone is to a relationship
• AO3 continued

  • This is a useful element of Rusbult’s model because it explains why women who are clearly not satisfied in a relationship may still return to it because they are committed
• AO3:

  • A limitation of Rusbult’s investment model is that it oversimplifies the idea of investment as a factor affecting commitment
  • Goodfriend and Agnew (2008) claim that the idea of investment shouldn’t just include the resources partners have already put in to a relationship, because at the start of a relationship they may not have put any resources into it (e.g. Bought a house)
  • Instead, they argue investment should include the investment partners make in their future plans because they are committed to make sure these plans work out
• AO3: limitation continued 


  • Therefore, the original model is a limited explanation of romantic relationships because it fails to recognise the true complexity of investment
• AO3:

  • A strength of the research supporting Rusbult’s investment model is the methodology used
  • Much of this evidence relies on self-report measures such as questionnaires and interviews
  • This is a strength because to fully test Rusbult’s model, psychologists need to assess each partner’s perception of factors such as investment and comparison to alternatives
• AO3 continued:

  • Self-report measures can gain rich, detailed qualitative accounts of each partner’s perception of investment and comparison to alternatives
  • This means the research supporting Rusbult’s investment model is high in validity because it is truly measuring the key components of the model