investment model

• • understanding why people persist in some romantic relationships but not others.​
  • Emphasises the central importance of commitment in relationships. ​
  • Rusbult devised the model to address the limitations of Social exchange theory. ​
• rusbult argued commitment depends on three factors?

  satisfaction level, CLAlt, and investment size
• • Satisfaction is based on the concept of comparison level (CL)​
  • A relationship is seen as profitable if it has many rewards and few costs. 
  • People will be satisfied if they are getting more out of the relationship than they expect (higher profit than CL) based on previous experience and social norms. ​

  ​
• • Rusbult realised that the CL and CLalt are not enough to explain commitment​
  • If they were, more relationships would end as soon as the costs outweighed the benefits or more attractive alternatives presented themselves. 
• rusbult introduced a third factor affecting committment: investment
• investment?


  measure of resources attached to the relationship, what would be lost if it was to end
• intrinsic ivestments ?


  resources we put directly into a relationship, they can be tangible such as money or intangible such as energy or effort
• extrinsic investment ?


  resources that didnt previously feature but are now associated with the relationship, can be tangible like a house/car or intangible things like shared memories and mutual friends
• a03?


  • strength: supporting evidence
  • data from 52 studies over 5 countries and 11000 participants was analysed to discover key variables in relationship maintenance
  • found: Clalt, investment size and satisfaction determine relationship commitment, committed relationships were stable and lasted longest
  • furthermore the findings applied to each gender, culture and orientation
  • therefore: large ad representative sample supports the model
• a03


  • may seem surprising that an individual experiencing violence would remain committed to the relationship as they experience low satisfaction ​
  • Investment Theory can explain why someone remains in an abusive relationship ​
  • Rusbult studied abused women at a shelter ​
  • Found that those most likely to return to an abusive partner reported having the greatest investments and the fewest attractive alternatives ​
  • Therefore, the investment model recognises that satisfaction/alternatives are not the only important factors in a relationship (which SET would claim)​
• a03?


  • There is more to investment than the resources you have already put into a relationship. ​
  • Goodfriend and Agnew (2008) extended Rusbult’s original model by including the investment romantic partners make in their future plans​
  • E.g. marriage and children ​
  • This shows the original model fails to recognise the true complexity of investment & how future plans influence commitment​
• a03?


  • weakness: methodological issues
  • based on correlational data, cause and effect can't be inferred, self report leads to social desirability bias
  • may lack internal validity