Social Exchange Theory: Relationships as Trade-Offs
This theory borrows its vocabulary from banking. Rewards, costs, profit, investment. It sounds cold applied to a marriage, and that is exactly the objection people make to it. It also predicts something the research keeps confirming: relationships in which both people feel the deal is fair are the happiest ones.
📘 What you need to know
Social exchange theory (SET) is an economic theory of relationships, proposed by Thibault and Kelley (1959), explaining how people assess the costs and benefits of a relationship.
For a relationship to thrive, each partner must feel rewarded and experience a sense of profit.
Couples negotiate the terms of exchange, either directly through conversation or indirectly through experience.
SET runs on the minimax principle: minimise your losses and maximise your profits, where profit = rewards − costs.
Rewards, costs and losses are entirely subjective and differ from relationship to relationship.
Relationships involve sacrifices that offset rewards; costs can destabilise a relationship if they lead to arguments and resentment, so a fine balance is needed.
Utne et al. (1984) found that couples in equitable relationships reported the highest contentment.
The minimax principle
The bottom row is the finding people forget. Utne’s over-benefited partners felt uneasy and guilty, which is not what a simple profit-maximising model would predict.
If SET were purely about maximising your own profit, being over-benefited should feel excellent. It did not. That result pushes the theory towards equity — fairness — rather than raw profit, and noticing the difference is a genuinely strong evaluative point.
Costs, sacrifices and negotiation
Couples negotiate the terms of exchange, sometimes explicitly and sometimes just by learning what works. One partner learns that praising the other’s cooking matters to them, so they do it, and the bond strengthens.
What counts as a reward is not shared. Being complimented on cooking may mean everything to one person and nothing to the other, so the same act can be a large reward or no reward at all.
Relationships require sacrifices that offset rewards — giving up nights out, living somewhere you would not have chosen, spending time with each other’s families. In the long run these can build a more rewarding relationship.
But costs can destabilise a relationship if they turn into arguments, conflict and resentment. Getting the balance right takes time, hard work and compromise on both sides.
Research support: Utne et al. (1984)
Aim: to investigate satisfaction in married couples in terms of how equitable each partner felt the relationship was.
Participants: 118 married couples in the USA, aged 16–45 (mean 26 for men, 24 for women). Most had dated seriously for over two years before marrying, and 74% had been married for four months or less.
Procedure: husbands and wives were interviewed separately about the history of the relationship, perceived equity or inequity within it, satisfaction with the marriage, and its perceived stability.
Results: couples in equitable relationships reported the highest levels of contentment and satisfaction. Partners who felt their benefits outweighed their costs — inequity in their own favour — felt uneasy and guilty about the imbalance.
Conclusion: the most successful relationships appear to be those in which both partners feel costs and benefits are divided fairly and equitably.
Read the 74% again. Three quarters of these couples had been married for four months or less. Newlyweds have not had time to build up the resentments and complaints that make perceived equity interesting. The study captures a honeymoon period, not a marriage, and a follow-up would have been far more informative.
Evaluation
Strengths
Therapeutic application. Couples therapy that increases rewards and reduces costs has been found to improve joint satisfaction and happiness, which suggests the model captures something real.
Real-world plausibility. Common sense says relationships do get judged on whether the costs outweigh the rewards, so the theory matches how people talk about their own relationships.
Utne interviewed partners separately, which stops one partner shaping the other’s answers — a sensible design choice for a sensitive topic.
Limitations
The key variables are subjective. Rewards, costs and profit differ from person to person, which makes SET very hard to operationalise and limits the reliability of the theory.
People are not businesses. Humans are complex and often unpredictable, so applying an artificial construct borrowed from economics to relationships is difficult, and both the theory and its research lack ecological validity.
It captures a moment, not a process. SET research tends to photograph a relationship rather than track it, which is a problem for something as changeable as a marriage.
It says little about why people stay in unrewarding relationships — and many people do, for reasons the balance sheet does not contain.
EXAM QUESTION
Evaluate one theory of the maintenance of personal relationships. [22]
Step 1: state the theory and its originThibault and Kelley (1959); an economic model using the language of banking and investment.Step 2: explain minimax and give the formulaProfit = rewards − costs; minimise losses, maximise profits.Step 3: use Utne, including the over-benefited finding118 US couples, separate interviews, equity linked to contentment, over-benefited partners felt guilty.Step 4: evaluate on measurement, realism and timeSubjective variables, an economic construct applied to people, newlywed sample, no follow-up, self-report biases.Strongest point: the guilt finding pushes the theory from profit towards equity
Link to concepts
Change
SET research tends to capture a moment in a couple’s relationship rather than tracking satisfaction over time. For findings in this field to have real validity the research should be longitudinal, because relationships are not fixed and stable — they change and fluctuate for financial, personal and practical reasons. Utne’s couples were newlyweds who had not yet had time to develop resentments about the equity of their relationship, so a follow-up study would have added a great deal.
Bias
Asking a couple about the state of their relationship invites several biases at once. Participants may want to present the relationship in the best possible light (social desirability bias), or may recall past episodes through a distorted lens (recall or hindsight bias). Some may report positive feelings about a partner while privately thinking negative things about them, which is cognitive dissonance in action.
💡 Exam tip
Write the profit formula out. It takes one line and defines the whole theory.
Use the word minimax and explain it rather than just naming it.
The over-benefited guilt finding is the most useful detail in Utne. It complicates the theory in an interesting way.
The 74% newlywed statistic is a specific, powerful criticism — far better than “the sample was limited”.
Stress that rewards and costs are subjective. It is both an explanation of the theory and a criticism of it.
Comparing SET with self-disclosure makes a strong conclusion: one sees relationships as trade, the other as trust.
⚠ Common mix-up
Treating rewards and costs as objective quantities. They are individual judgements.
Saying people always leave unprofitable relationships. Many do not, and SET struggles to explain why.
Assuming over-benefited partners are happiest. Utne found they felt uneasy and guilty.
Confusing equity with equality. Equity is a fair ratio of what each puts in and gets out, not identical amounts.
Calling Utne an experiment. It used separate interviews and is correlational.
Forgetting that most of the sample were newlyweds. It changes what the findings can support.
That completes Topic 3: Human Relationships. A good way to revise it is to line the four relationship theories up against each other — chemistry, calculation, disclosure and exchange — and ask which part of a real relationship each one actually explains. Then start again at Acculturation and Its Effect on Mental Health and see how much more of the group behaviour material connects.
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