Theories of relationship formation

Black - AO1 - Description
Blue - AO2 - Evaluation - studies
Red - AO2 – Evaluation - evaluative points/IDAs

Filter Theory

Kerckhoff and Davis proposed the filter theory, suggesting that relationship formation is based on systematic filtration of possible partners on three levels – starting from a "field of availables."

1 – Social demographic variables. Subconsciously, we filter down to a pool of people belonging to similar social demographics to us – same school, town, workplace etc. Individual characteristics play a very small role at this stage.

2 – Similarity of attitudes and values. Here, the pool is filtered based on the law of attraction – greater similarity brings better communication and a better chance of relationship developing further. Having similar hobbies, beliefs, and interests increases the chance that a relationship will develop further and more deeply.

3 – Complementarity of emotional needs. Once a couple is established in a fairly long term relationship, the relationship will develop for better or for worse depending on how well they fit together as a couple and mutually satisfy their needs. Similarities in the amount of emotional intimacy, sex, social interaction and physical proximity required increases the chance that the relationship will be successful in the long-term.

Kerckhoff and Davis provide supporting evidence for filter theory with their longitudinal study of student couples together for less or more than 18 months. Attitude similarity was the most important factor up until 18 months, after this, psychological compatibility and ability to mutually meet needs was the most important factor in determining the quality of the relationship.

The theory can be considered to have a degree of face validity, as it is common sense to assume that similarities in demographic factors, attitudes and values systems would lead to a more happy and successful relationship and would thus be filters that we apply in the selection process.

Spreecher challenged this hypothesis, suggesting that social variables are not the only initial filter, and that couples matched in physical attractiveness, social background and interests were more likely to develop a successful relationship.  This is supported by Murstein’s match hypothesis, which suggests that a significant factor in early attraction is the couple being of similar attractiveness levels – though people may desire the most physically attractive partner, they know in reality they are unlikely to get or to keep them, so they look for people of a similar attractiveness to themselves.

Gruber-Baldini et al (1995) carried out a longitudinal study of couples aged 21 and found that those who were similar in educational level and age at the start of the relationship were more likely to stay together and have a successful relationship, suggesting these two as factors ignored by Kerschoff and Davis in their Filter Theory.

An issue with filter theory is that it could be considered to be overly deterministic, failing to capture the dynamic and fluid nature of human relationships by its division into three distinct stages, and failing to take into account the role of free will in partner selection.  Not all couples will have the same priorities in their relationships at exactly the same stages, and to suggest so is too nomothetic, ignoring individual differences between couples. 

Another issue with filter theory is that it could also be considered to be overly reductionist, seeking to explain the complex nature of relationship behaviour as a result of simple filtration processes, selecting a partner through a process of elimination from a “field of availables.” This is potentially an oversimplification of relationship formation, and cannot definitively explain the formation of homosexual romantic relationships. Homosexual couples may not necessarily have the same experiences that lead to their relationship being initiated as heterosexual couples, so the theory could be considered to have a heterosexist bias.

Reward/Need Satisfaction Theory

Reward/Need satisfaction theory suggests in order to progress from early attraction, the two people need sufficient motivation to want to continue getting to know each other. Long-term relationships are more likely to be formed if the partners meet each others' needs, providing rewards in the form of fulfilment of a range of needs - including biologically based needs such as sex and emotional needs such as giving and receiving emotional support, and feeling a sense of belonging.

This theory works on two key principles of the behavioural approach: operant conditioning and classical conditioning. Through classical conditioning, doing activities you enjoy with your partner leads to a conditioned response of happiness to the conditioned stimulus of your partner, leading to an intrinsic feeling of happiness while being around your partner. Through operant conditioning, the sense of belonging and the fulfillment of emotional needs such as intimacy function as rewards in the positive reinforcement process, leading to a strengthened relationship between the couple - they will like each other more and want to spend more time together.

Supporting evidence for this theory comes from Argyll's explanation that relationship formation works as a means to the satisfaction of motivational systems. Argyll (1994) outlined several key motivational systems underpinning social behaviour, and explained how relationship formation satisfies several social needs, namely: Biological needs - collective eating, sex, Dependency - being comforted, Affiliation - a sense of belonging, and Self-esteem. These results support the theory of attraction developing around need fulfilment, with partners acting as means to the fulfilment of certain social needs. 

Further supporting evidence for reward/need satisfaction theory comes from Aron et al (2005), who gave 17 participants who reported being "intensely in love" MRI scans, finding that dopamine-rich areas of the brain showed much more activation when the participant was shown a photo of the person with whom they had fallen in love, in contrast to someone they just liked. The amount of dopaminergic activity was positively correlated with the degree to which they felt in love. This supports the role of operant conditioning as a component of reward/need satisfaction theory - just seeing the person they loved stimulated the release of dopamine in the brain's reward circuits.

In some ways, this study treated psychology as a science by using MRI equipment to give objective, scientific results, measuring the activation of dopamine reward circuitry in the brain. This gives the study a high degree of internal validity, providing an objective measurement of the brain activity it claims to measure. However, in some aspects this study was less scientific - the self-reported description of "very much in love" cannot be scientifically and objectively verified, and is not falsifiable.

A study by May and Hamilton (1980) also supports reward/need satisfaction theory, providing supporting evidence for the role of classical conditioning. Female participants evaluated photographs of men while listening to either rock music that stimulated a positive mood, to music that stimulated a negative mood, or no music at all. The participants gave much more positive evaluations of personal character, physical attractiveness and general attraction in the rock music condition than in the other two, suggesting that an association had formed between the positive feeling from the music, and the men they were evaluating.

Attraction does not necessarily equal formation of relationships - this theory ignores matching and the opportunity to meet. These studies and the theory only explain how a relationship develops once there is already a degree of mutual attraction between two people, not how this initial attraction develops, so they do not fully explain the initiation of relationships.

An issue with May and Hamilton's study is that it was only carried out on female participants. Research and evolutionary theories into sexual selection suggest that attraction develops differently in males and females, so to generalise from males to females without taking these potential gender differences into account would be beta gender bias, and likely to be an inaccurate generalisation. Research has suggested that males prioritise physical appearance in a partner, while females prioritise status and power - these differences in priorities must be taken into account.

Another issue with reward/satisfaction theory is that it is overly environmentally reductionist, explaining a complex human behaviour to be a result of simple behavioural learning based around reward mechanisms. The theory ignores social, cognitive and biological factors that could play a role in attraction, such as the social demographic variables described by Kerckhoff and Davis in their filter theory.