Theories of Romantic Relationships

This lesson examines three major psychological theories that attempt to explain why romantic relationships are maintained and why some relationships succeed while others fail. Each theory takes an economic or exchange-based approach, treating relationships as involving costs, rewards, and investments.

Key Definition: Comparison Level (CL) is the standard against which a person judges the quality of their relationship, based on past experiences and expectations. If the current relationship exceeds the CL, it is judged as satisfactory.

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Social Exchange Theory (Thibaut & Kelley, 1959)

Social exchange theory (SET) proposes that people evaluate relationships in terms of costs and rewards, much like a financial transaction. The theory rests on the assumption that humans are fundamentally motivated to maximise rewards and minimise costs.

Key Concepts

Rewards may include companionship, sex, emotional support, financial security, and social status. Costs may include time, effort, emotional stress, financial expenditure, and loss of freedom.

The outcome of a relationship is calculated as:

Profit = Rewards − Costs

If the profit is positive, the person is likely to judge the relationship as satisfactory.

Comparison Level (CL)

Each individual has a comparison level — an internal standard of what they expect from a relationship, based on:

• Previous relationships
• Social norms and media portrayals
• Self-worth

If the current relationship exceeds the CL, the person feels satisfied. If it falls below the CL, dissatisfaction arises.

Comparison Level for Alternatives (CL-alt)

The CL-alt is the person's assessment of whether they could obtain a better outcome from an alternative relationship (or from being single). Even if the current relationship is above the CL, a person may leave if an alternative offers a higher perceived reward.

• If CL-alt > current relationship → the person may leave.
• If CL-alt < current relationship → the person stays, even if not perfectly satisfied.

Stages of Relationship Development (Thibaut & Kelley)

Stage	Description
Sampling	Exploring rewards and costs of different relationships (by direct experience or observation)
Bargaining	Early stage: partners exchange rewards and negotiate costs
Commitment	Costs and rewards become more predictable; partners settle into the relationship
Institutionalisation	Partners are firmly established; norms and expectations are embedded

Evaluation of Social Exchange Theory

Strengths (AO3):

• The theory explains why some people remain in unsatisfying relationships — their CL-alt may be low (e.g., no perceived alternatives, financial dependence).
• Research support: Simpson et al. (1990) found that participants already in relationships rated opposite-sex people as less attractive, consistent with lowering the CL-alt to maintain commitment.

Limitations (AO3):

• Selfish model: SET assumes people are fundamentally selfish, constantly monitoring costs and rewards. In reality, many people in loving relationships do not engage in such "mental accounting."
• Culturally biased: SET reflects Western, individualistic values. In collectivist cultures, relationships may be maintained for family honour or duty rather than personal reward.
• Difficulty operationalising: What counts as a "cost" or "reward" is subjective and varies between individuals, making the theory hard to test empirically.
• Does not explain why people stay in abusive relationships very well — unless CL-alt and learned helplessness are invoked.

Exam Tip: When evaluating SET, a strong AO3 point is to contrast it with equity theory, arguing that equity theory offers a more balanced view because it considers fairness, not just profit.

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Equity Theory (Walster et al., 1978)

Equity theory is an extension of social exchange theory that focuses not on profit, but on perceived fairness. The central principle is that people are most satisfied in relationships where the ratio of inputs (costs) to outputs (rewards) is roughly equal for both partners.

Key Concepts

Equity does not mean equality — it means that the ratio of what each partner puts in and gets out is perceived as fair. A relationship is equitable when:

Partner A's Rewards / Partner A's Costs ≈ Partner B's Rewards / Partner B's Costs

Over-Benefited and Under-Benefited Partners

Status	Experience	Response
Equitable	Both partners perceive fairness	Satisfaction; relationship maintained
Over-benefited	One partner receives more than they contribute	Guilt, discomfort
Under-benefited	One partner contributes more than they receive	Anger, resentment, distress

According to Walster et al., both over-benefited and under-benefited partners experience distress, but the under-benefited partner typically experiences the most dissatisfaction. Partners will attempt to restore equity either by:

• Changing the amount they put in or get out of the relationship
• Cognitively reframing the situation (e.g., "she works harder because she enjoys it")
• Leaving the relationship

Evaluation of Equity Theory