Equity Theory is another economic exchange theory which was derived from Social Exchange Theory by theorists such as Hatfield et al. (1979). It assumes that people strive to achieve fairness in their relationships and feel distressed if they perceive unfairness (Messick and Cook, 1983). This is more plausible than Social Exchange Theory, as the latter implies that people are inherently selfish and only seek rewards, as opposed to balance and stability. This is supported by Walster et al. (1978), who put forward four principles for equity theory: that individuals try to maximise the rewards and minimise the costs; that there is a negotiation to produce fairness; that if a relationship is unfair or inequitable it produces stress; and that the disadvantaged person will try hard to make the relationship more equitable.
Evidence for this comes from Rusbult (1983), who found that when people were deciding whether to end a relationship, they weighed up the rewards and costs of the relationship and considered the alternatives open to them. This implies that for a relationship to continue, there is an assessment of the rewards and costs of the relationship and of alternatives, therefore supporting economic exchange theories.
However, despite the face validity of theories such as Equity Theory, research into economic exchange theories has been associated with contrived methodologies that have little ecological validity. There has also been a lot of emphasis on short-term relationships and little consideration of, for example, marriages; and the research also did not examine the longer-term dynamics of relationships over time.
These dynamics can be examined in greater detail, however, when ideas such as maintenance strategies are taken into account; for example, avoidance strategies, whereby one partner avoids discussion of the future with the other partner if they feel that the other partner does not want to continue the relationship but they do (Ayres, 1983). Supporting this, Dindia & Baxter (1987) identified forty-nine maintenance strategies, and found that couples who were married used less such maintenance strategies than those who had not been in a relationship for long. This may be because the couple understand each other and do not need to put in any active effort, or because they are kept in the relationship out of force of habit. Indeed, it may be that couples only consciously realise minor previously-unnoticed interactions after they break up (Morgan, 1986). However, again this research may be criticised for relying heavily on dyadic heterosexual relationships, and may not apply to other types.
Self-disclosure, according to Sternberg (1986), may also be essential in maintaining a relationship. This is the revealing of personal and sensitive information and is a significant part of intimacy. This is supported by Altman & Taylor (1973), whose Social Penetration Theory states that relationships require self-disclosure on both sides. This must not happen too rapidly as the other partner may feel threatened, but people who have just met tend to follow the norm of self-disclosure reciprocity, and match the level of self-disclosure of the other partner. However, as a relationship develops, depenetration may occur, whereby people respond to their partner's self-disclosure by offering support and understanding as opposed to simply engaging in self-desclosure, as supported by Archer (1979). According to Tolstedt & Stokes (1984), depenetration may occur in two main forms: refusing to reveal intimate information altogether, or talking intimately about only a few topics, which are often chosen in order to hurt the other person.
Commitment is also undoubtedly an important factor, and is characterised by determination to continue the relationship. Rusbult (1980) outlined an investment model containing three factors: satisfaction, the perceived quality of alternatives, and how much time, money and effort is invested in the relationship. Lund (1985) found that investment size was more important in determining the level of commitment than were satisfaction or rewards. Michaels et al. (1986) found that commitment was stronger when the outcomes of the relationship exceeded those anticipated in alternative relationships, and that the extent to which relationship was equitable did not predict commitment. This is therefore in direct contrast with Equity Theory. However, Rusbult's approach may not be sufficient, since the three factors are not entirely independent of each other, so, for example, an individual may invest more in a relationship as a result of being satisfied with it. Additionally, she focussed heavily on short-term rather than long-term relationships.
These theories are largely concerned with the interactions between only the two people in the relationship, which may be a reductionist idea ― Hagestad & Smyer (1982) said that social factors such as the expectations of friends and family can be significant in maintaining relationships. This identifies external factors not considered in other research above, and may be particularly relevant when examining relationships in collectivist cultures, where the expectations and opinions of others may have a much larger impact than in individualist cultures.
