Rusbult's Investment Modell

• The investment model was developed by Rusbult et al. as a further development of Social Exchange Theory.
• Parents who are committed to their relationship and invest in it have a higher chance of ensuring their children's survival and therefore of passing on their genes.
• The investment model supports the nature side of the nature-nurture debate.
• The rationale for developing SET further was that many couples stay together despite the costs outweighing the rewards, indicating that there must be other factors maintaining their commitment.
• According to Rusbult's investment model, there are three major factors that maintain commitment in relationships: satisfaction level, comparison with alternatives and investment size.
• Satisfaction level and comparison with alternatives in the investment model are based on the comparison levels concept from Social Exchange Theory.
• People will have a high level of satisfaction with relationships if they have more rewards (companionship, attention, emotional support) and fewer costs (arguments, time).
• People are committed to relationships if, when asking themselves, 'Is there a better alternative to satisfy my needs?' the answer is 'no'.
• Alternatives in the investment model can include staying on their own and not engaging in romantic relationships at all, as well as finding a new partner.
• The most important factor that maintains commitment to a relationship according to Rusbult's investment model is investment.
• Investment in the investment model refers to the number of resources, both tangible, like money or possessions, and intangible, like happy memories, that people will lose if they leave relationships.
• The investment model proposes two types of investment: intrinsic and extrinsic.
• Investment in romantic relationships is a complex phenomenon, consisting of many different factors, which makes the investment model reductionist.
• The investment model lacks predictive validity as it fails to predict which types of investment and how much investment will lead to long-term commitment to a relationship.
• Culture bias doesn't seem to be an issue for the investment model as Le and Agnew’s (2003) meta-analysis of 52 studies found support for the investment model across individualist and collectivist cultures, such as in the USA (individualist culture) and in Taiwan (collectivist culture).
• Some psychologists think that Rusbult’s idea of relationship investment is oversimplified.
• The lack of predictive validity makes the investment model less scientifically rigorous as the ability to predict people's behaviour, in this case, whether or not they will stay committed to the relationship, is one of the main goals of psychology as a science.
• Most evidence for the investment model comes from interviews and questionnaires, which are known to be subjective and unreliable.
• The investment model, as an explanation of relationship maintenance, is also shown to be valid for different sub-groups, such as friendships; homosexual relationships; and cohabiting couples, etc.
• The universality of the investment model suggests that the human need for investment and commitment to relationships developed through the process of natural selection to help people survive and reproduce.
• According to Goodfriend and Agnew (2008), it is not just things we bring to the relationships that could count as investment, but also a couple's plans for their future.
• Using self-report techniques to test the investment model may provide a more realistic picture of reasons for relationship satisfaction and how it is related to investment and commitment, therefore making the investment model more valid.
• Intrinsic investment in the investment model comprises the things we put directly into the relationship, such as effort, money, possessions, self-disclosure.
• Ridiculing alternatives – minimising the advantages of potential alternatives and viewing them in a negative light.
• Research into abusive relationships supports the idea that the investment model can be applied, for example, Rusbult and Martz, in their study of 'battered' women, found that women were more likely to return to an abusive partner if they felt they had invested in the relationship and they didn't have any appealing alternatives.
• Impett, Beals and Peplau (2002) conducted a longitudinal study using a large sample of married couples over an 18 months period.
• Similar trends were found in Le and Agnew’s (2003) study, which conducted a meta-analysis of 52 studies, featuring 11,000 participants in total, and discovered that satisfaction, comparison with alternatives and investment greatly contributed to commitment; and that commitment was a defining feature of long-lasting relationships.
• One strength of the investment model is that it is supported by numerous research studies, such as Le and Agnew (2003), which found that satisfaction, comparison with alternatives and investment greatly contributed to commitment.
• The investment model provides a plausible explanation for why people stay in abusive relationships, as it suggests that if a partner feels that the investment they made into relationships will be lost if they leave, they are more likely to stay in a relationship even when the costs are high (such as physical or emotional abuse) and rewards are few.
• Research examining the investment model includes numerous studies supporting the model.
• The majority of research into the investment model is correlational, so psychologists are unable to conclude that investment causes commitment in relationships.
• Rhahgan and Axsom (2006) studied a group of women and found that all three factors identified by Rusbult et al (satisfaction, comparison with alternatives and investment) featured in participants' decision to stay with their partner.
• The stability of the relationships positively correlated with commitment shown by the partners in the study by Impett, Beals and Peplau (2002).
• Extrinsic investment in the investment model refers to the things that are brought to people's life through the relationships, such as children, friends and shared memories.
• Rusbult et al. concluded that the bigger the investment, the more likely people are to stay in relationships.
• In addition to the factors influencing partners’ commitment, Rusbult et al. also identified maintenance mechanisms partners use to keep relationships going.
• Maintenance mechanisms in the investment model include accommodation, willingness to sacrifice, forgiveness and positive illusions.