Chapter 6:

Interdependency refers to our reliance on others, and they on us, for valuable interpersonal rewards.



     The mutual exchange of desirable rewards between people is known as social exchange (Blau, 1964; Homans, 1961).

     Interdependency theories suggest that people seek relationships that provide the maximum reward at minimum cost (Kelly & Thibaut, 1978).





     Rewards of social interactions are anything that is desirable and brings fulfillment to a recipient and can range from impersonal benefits to personal intimacies.

     Costs are undesirable, punishing outcomes or experiences.

     The net profit or loss from an interaction is called an outcome.

What Do We Expect From Our Relationships?

     Everyone has a comparison level (CL) or the value of the outcomes one expects from their social interactions, according to interdependency theory.

     Comparison levels are based on people’s past experiences.

     We use our comparison levels as a way to measure our satisfaction within a relationship.

How Well Could We Do Elsewhere?


 People use a comparison level alternative to determine if they could do better elsewhere.

 Deciding whether to stay or leave a relationship  depend on whether those involved think they can do better elsewhere or whether they are better off in their present relationship.

      Caryl Rusbult has shown that people’s investments in their present relationship also influence their decision to stay or leave.



How Well Could We Do Elsewhere?

     Factors such as self-esteem and  access to information affect people’s thoughts and perceptions and can thus influence their comparison level alternative (Kiesler & Baral, 1970; Rusbult & Martz, 1995).

     The degree to which people attend to their alternatives also influences their comparison level alternative (Miller, 1997).

A Social Exchange Model of Relationship Development

      Social exchange theory is based on an economic model of human behavior.

      Social exchange theory assumes that people are motivated by the desire to maximize profits and minimize losses in social interactions.

      The various components of Social Exchange Theory are:

    Rewards - Costs = Outcome.

    Outcome - Comparison Level (CL) = Satisfaction Level

    Outcomes – CLalt = Dependence/Independence

    Satisfaction - Alternatives + Investments = Commitment.

A Social Exchange Model of Relationship Development:
 Rewards and Costs:

      In the terms of social exchange, the outcome of a relationship is determined by rewards minus costs.

      It is generally true that happy couples behave in more rewarding ways toward each other than do unhappy couples.

      Rewards also contribute to the endurance of a relationship.

      Costs may be less important in the early days of a relationship than after it has been established.

A Social Exchange Model of Relationship Development:
 Rewards and Costs (continued):

      Both rewards and costs are based on subjective assessments of reality.

      These assessments are subject to bias and distortion,
and partners may disagree about their assessments of the behaviors in their relationship.

      An individual who displays an egocentric bias overestimates his or her own contribution to a particular outcome,
relative to the perceived contribution made by the partner.

      Relationship partners may also disagree about how much an item or activity is worth, making it more difficult to provide effective rewards to each other.

A Social Exchange Model of Relationship Development:

      The comparison level (CL) refers to the average, overall outcome an individual expects in an intimate relationship.

      From a social exchange perspective, satisfaction is determined by both a person's initial CL and the outcome of the relationship.

      The lower the CL (i.e., the lower a person's expectations), the less rewarding the relationship needs to be to produce satisfaction.

A Social Exchange Model of Relationship Development:

      The comparison level for alternatives [CLalt] refers to the average, overall outcome an individual expects from an alternative relationship or lifestyle.

      "CLalt" affects commitment to the relationship.

      The higher the "CLalt," the less commitment there should be to the existing relationship.

Four Types of Relationships

      Interdependency theory suggests that four types of relationships arise, depending on the quality level of people’s comparison levels, comparison level alternatives and outcomes.

      These types are: happy, stable relationships; unhappy, stable relationships; happy unstable relationships; and unhappy, unstable relationships.

Types of Relationships

      Happy, Stable Relationship







      Happy, Stable Relationship








      Unhappy, but stable relationship







      Happy, but unstable relationship








Unhappy, unstable Relationship








  Unhappy, unstable Relationship







Power and Independence (Box 6.1)

      The difference between two romantic partners dependence dictates who has more power.

      This often happens when both partners receive more outcomes than they expect (CL) and more than they think they will get elsewhere (CLalt).

      The principle of lesser interest proposes that the partner who is less dependent on a relationship has more power in that relationship (Waller & Hill, 1951).

Power and (In)Dependence

      Betty’s alternatives are better than Barney’s so she has more power in the relationship.


      Betty and Barney’s Outcomes


      Betty’s CLAlt


      Barney’s CLAlt

CL and CLalt as Time Goes By

      People’s comparison levels fluctuate along with the outcomes they receive.

      If someone’s comparison level rises but the outcomes remain the same, the person will not be satisfied.

      Some believe that our society’s higher CLs are partly to blame for less marital happiness compared with married couples 30 years ago (Glenn, 1996).

CL and CLalt as Time Goes By

     Cultural changes such as more men being available, more financial freedom for women and less barriers against divorce have also influenced increases in our CLs and CLalts leading to unhappy, unstable relationships (White & Booth, 1991).


A Social Exchange Model of Relationship Development:
 Alternatives (continued):

      Some overall levels of "CLalt" are set by broad societal trends, such as sex ratios.

      Sex ratios indicate the overall availability of potential other-sex partners within a given population.

      When there are more men than women,
sex ratios are high;

      When there are fewer men than women,
sex ratios are low.

A Social Exchange Model of Relationship Development:
 Alternatives (continued):

      Baby boomers (those born between 1945 and 1957) experience low sex ratios, due to the yearly increase in births and the tendency of women to marry slightly older men.

      Whites born in the 1970s will experience high sex ratios.

      However, White women over 40 and Black women of all ages will still tend to face a scarcity of available male partners.

A Social Exchange Model of Relationship Development:

      An investment is something an individual puts into a relationship that can not be recovered should that relationship end.

      In general, investments strengthen commitment.

      When investments in a relationship produce rewards from that relationship, commitment is accompanied by increased satisfaction with the relationship.

      But when heavy investments produce little satisfaction, individuals may become entrapped in the relationship.

    In entrapment, commitment to a failing course of action is increased by an effort to psychologically justify the investments that have been already made.

A Social Exchange Model of Relationship Development:
 Investments (continued):

      Dissonance theory provides a broad theoretical framework that can account for entrapment effects.

      Dissonance is an uncomfortable state that arises from inconsistencies among thoughts, feelings, and behaviors.

      Voluntary actions (but not involuntary actions) that are inconsistent with thoughts and feelings create dissonance.

      It is dissonant to voluntarily agree to engage in difficult and effortful intimate behavior that produces unsatisfying relationship consequences.

A Social Exchange Model of Relationship Development:
 Investments (continued):

      But, people can reduce dissonance by changing their attitude toward such consequences.

      Thus, subjects who engaged in effortful activities to become part of a boring group made more positive evaluations of the group than subjects who had expended little or no effort to join the group.

      It is also dissonant to know about problems in an intimate relationship, but go ahead and make a commitment to that relationship anyway.

      To reduce dissonance, people in these relationships can increase their positive attitude toward the partner.

A Social Exchange Model of Relationship Development:
 Investments (continued):

      Thus, newly engaged students who were aware of more problems before they became engaged reported a more fulfilling relationship after the engagement, relative to students who were aware of fewer problems.

      From the perspective of dissonance theory, we come to love that for which we have suffered in the past and that from which we suspect we will suffer in the future.

Commitment to A Relationship:

      Commitment refers to the strength of one's intentions to continue the relationship.

      In general, the more freely, frequently, and publicly we act, the more we become committed to the action and to the attitudes it implies.

Commitment to A Relationship (continued):

      Among college students engaged in dating relationships, commitment was the best single predictor of the endurance of their relationship across a two-month period.

      Commitment to a relationship increases the endurance of that relationship because we (1) cut off outside options, (2) resist efforts by outsiders to make us change our position, and (3) become more susceptible to influence from the partner.

When Commitment Fails

      But commitment is no guarantee that a relationship will last a lifetime.

      Indeed, commitment can have some negative effects.

      In a committed relationship, total expected rewards are higher, but so are total expected costs--as both rewards and costs are anticipated to continue in the future.

      And, it may be more difficult to make compromises and accommodations in a committed relationship, because of fears that giving in now may imply the need to give in later as well.


     Rewards and costs are important factors that contribute to relationship satisfaction and stability.

The Economies of Relationships

      Research has shown that unpleasantness is often part of many relationships.

   For example, 44% of people are likely to be annoyed by a friend or lover, on any given day(Averill, 1982).

   And most young adults state that their lovers were too critical, stubborn, selfish and unreliable at least once within the last week (Perlman, 1989).

   In addition, spouses tend to disagree more openly, interrupt each other more and show more signs of frustration then they do when arguing with someone else (Vincent, Weiss & Birchler, 1975).


Rewards and Costs as Time Goes By

      At the beginning of relationships, those that will succeed are just as rewarding as those that will end quickly.

      Rewards increase over time as do the costs in a relationship.

      In unsuccessful relationships, costs rise but rewards drop, decreasing satisfaction (Eidelson, 1980).

Rewards and Costs as Time Goes By

     Researchers have demonstrated that relationship satisfaction declines in the first few years after marriage (Karney & Bradburry, 1997; Kurdek, 1998; Leonard & Roberts, 1997).


     Through lack of effort, access to weaponry, unwelcome surprises, unrealistic expectations, and because interdependency is a magnifying glass, people often fail to maintain the outcomes that lead them to marry (Miller, 1997).

  Interdependency magnifies conflict and friction. And frequent interaction can aggravate annoyances.



Are We Really This Greedy?

     While research supports interdependency theory fairly well, the overall picture of relationships is not complete.

     There are good reasons why people will want their partners to do well and maintain a happy, stable relationship.


The Nature of Interdependency

     Interdependent partners have a stake in keeping each other happy.

     Some actions that might be costly between strangers can be rewarding in a close relationship, since they give pleasure to one’s partner and increase the likelihood of receiving valuable rewards in return, (Kelly, 1979).

Exchange Versus Communal Relationships

      People seem to realize that rewarding interdependency is more likely to develop when they are not being greedy by simply pursuing profits.

      Clark and Mills (1979, 1993) propose that exchange relationships involve the desire for and expectation of immediate return for benefits given. And communal relationships involve the desire for and expectation of mutual responsiveness to each other’s needs.

Differences Between Exchange and Communal Relationships


      We do a Favor

     prefer pay back immediately

      Others do us a favor

    Prefer being asked for immediate repayment

      Working with others on joint task

    Ensure our contributions are distinguished from others





      Don’t prefer those who  repay immediately

      Prefer those who do not seek immediate repayment

      Don’t make clear distinctions between other’s work and ours



      When others need help

    Track others needs only when they can return favors

      When we help others

    Our moods and self-evaluations change slightly

      When we don’t help others

    Our moods do not change


      Keep track of others needs even when they are unable to return favors

      Our moods brighten and our self-evaluations improve

      Our moods get worse


    Communal relationships typically characterize meaningful romantic relationships, while both communal and exchange relationships are involved in friendships (Clark & Mills, 1993).

Equitable Relationships

      While being nice is important in a relationship, it is also important to be fair.

      Equity occurs when both partners gain benefits that are proportional to their contributions (Hatfield, 1983; Sprecher & Schwartz, 1994).

      A relationship is fair when a partner who is contributing more is also receiving more, according to equity theory.

      People are “overbenefited” if they receive more than they deserve and they are “underbenefited” if they receive less than they deserve.


             Your outcomes       = Your partners outcomes

      Your contributions   Your partners contributions


Partner X         Partner Y        Partner X     Partner Y

             80/50    =   80/50           (d) 80/50    >    60/50

             20/100  =   20/100         (e) 80/50    <    80/30

             50/25    =   100/50

The Distress of Inequity

      Equity theory assumes that people will want fair relationships and will be distressed if the relationship they are in is not fair, especially if they are “underbenefiting.”

      The theory predicts that people who are “overbenefiting” will be less happy than those in equitable relationships and those who are “underbenefiting” will be least happy of all (Hatfield, 1983).

Ways to Restore Equity

      Restore actual equity by changing one’s outcomes or making changes in contributions can sometimes restore equity.

      People may also change their perceptions of the relationship to convince themselves that it is equitable even when it is not.

      Sometimes none of these efforts restore equity leading people to have affairs or end the relationship (Prins, Buunk, & VanYperen, 1993).

How Much is Enough?

      Research has shown that both the global quality of outcomes people receive in a relationship and underbenefiting are important factors that predict how satisfactory and enduring a relationship will be (Feeny, Peterson, & Noller, 1994; Sprecher, 1999).

      Outcome levels seem to be more important than inequity.

   For example, if one’s outcomes are poor, it will not matter how fair they are and if one’s outcomes are great, inequity will not matter much.


    Is simple greed a a good description of people’s behavior in relationships?


      Relationship science gives a qualified yes as an answer.  People are happiest when their rewards are high and costs (and expectations) are low.  But we have a stake in satisfying our partners too, because we depend on them for the rewards we seek  in intimate relationships.  Perhaps encouraged by selfish motives, we protect the well- being of our partners and rarely exploit them if we want the relationships to continue, and we can behave thoughtfully, generously, and lovingly even if there are greedy and self-serving motives involved too.

The Nature of Commitment

Happy dependence on an intimate partner leads to commitment, the intention to continue in a relationship.

   The investment model links commitment to all the elements of social exchange associated with people’s comparison levels and comparison level alternatives (Rusbult et al., 1994; Rusbult, Wieselquist, Foster, & Witchler, 1999).


The Nature of Commitment

      The investment model suggests that satisfaction increases commitment, however, high quality alternatives decrease  commitment.

   People who have appealing alternatives luring then away from their current partners are less likely to stay in that relationship.

Still, people do not always pursue alternatives if the costs of leaving their present relationships are too high.



      Satisfaction, the quality of alternatives, and the size of one’s investments each tell us something useful about the level of a person’s commitment.

      The investment model is good at predicting

    how long relationships will last, faithfulness, and even if battered wives will leave their husbands.

The Nature of Commitment

      Other theorists argue against  commitment being a unitary concept, (only one type of commitment) an assumption made by the investment model.

      Michael Johnson (1999) proposes three types of commitment:

    Personal commitment—people wanting to stay in a relationship because they are attracted to their partners and the relationship is satisfying.

    Straint commitment—people feeling they have to continue in the relationship because the costs would be too high if they left.

    Moral commitment—people feeling they ought to stay in the relationship because they do not want to break promises or vows.


      Research shows that the three types feel different to people.

   Ex. In long-distance romantic relationships moral commitment is better at predicting the survival of the relationship during the separation than personal commitment.


The Consequences of Commitment

      When people are committed to a relationship they tend to display a long-term orientation and tend to view themselves and their partners as a whole or single entity (Agnew, Van Lange, Rusbult, & Langston, 1997).

      Commitment leads people to protect and maintain the relationship, even when it is costly.


The Consequences of Commitment

      Committed people engage in cognitive and behavioral strategies that preserve and enhance the relationship.

    Accommodative behavior – restraint from provocation, tolerance, lack of retaliation.  Not motivated by weakness, but an effort to protect the relationship from harm.

    Willingness to sacrifice – putting self-interest aside for the good of the relationship i.e., do things wouldn’t do if alone and not dothings would do if alone.

    Perceived superiority – people often think they enjoy more rewards and suffer fewer costs than other people in relationships.