9.2.3 Filter Theory

• A filter is a type of criterion applied to a field of availables to determine whom amongst them is likely to provide a good ‘match’ 
• Kerckhoff & Davis (1962) suggested filter theory after conducting research with real-life couples, asking them what it was that attracted them to each other in the first place and why the relationship was (up to that point) successful
• Proximity is key when it comes to the first stage of filtering i.e. who you live/work nearest to
• Hollywood films may romanticise long-distance love but the reality is that relationships tend to form based on practicality i.e. who is easier to form a relationship with - someone who lives around the corner or someone who lives on the other side of the world?
• Kerckhoff & Davis (1962) concluded that people apply a set of criteria - filters - which help them to narrow down the field of availables to a field of desirables who represent the best choice in terms of potential partner
• Thus, a filter in a romantic relationship is any parameter that is applied to a set of criteria used to sort the ‘sheep from the goats’ as it were!
• Filters tend to fall within the three general levels described below but they are entirely subjective as one person’s idea of ‘desirable’ is another person’s idea of ‘I’ll pass, thank you’

A field of availables will be different for each individual - and age is no barrier in the search for the perfect partner!

• Social demography refers to the first level of filtering as it takes in a broad sweep of variables such as geographical location, workplace, hobbies, lifestyle, habit,  all of which determine who an individual is likely to come into contact with as part of their everyday life
• Festinger et al. (1950) found that students who lived in adjoining rooms or the same corridor of student accommodation blocks formed more and closer friendships with each other than with students who lived on a different corridor, floor or block, thus proximity is key when it comes to the first stage of filtering i.e. who do you live/work in closest proximity to?
• Daily habits such as going to the gym, popping into the same cafe for your morning latte on the way to work, and taking your dog for a walk every day can all lead to encounters with potential partners
• Level of education, religious and political beliefs (which may also involve attending church or meetings) also contribute to this first level of filtering as they involve the meeting of like minded people which can be important for establishing a relationship in the first place

• Similarity in attitudes describes exactly what the name suggests: people tend to want to form relationships with those who share their attitudes, outlook, worldview etc.
• Similarity in attitudes forms the second level of filtering as the field of availables has already gone through the first filter so it is at this point that more stringent criteria are applied i.e. nobody wants to date someone just because they live around the corner; there has to be some meeting of minds involved
• Interestingly it seems that it is only in the first 18 months or so of relationship formation that similarity in attitudes is a key factor (Kerckhoff & Davis, 1962); once the relationship is established this filter has been passed and thus the need to establish similarity is not as vital
• Relationships based on physical attraction only are likely to ‘fizzle out’ after the first heady rush is over: if the couple do not share values, beliefs and attitudes then there is no firm foundation on which to build the relationship (Byrne, 1997)

This sporty couple are clearly on the same page when it comes to physical fitness which should help to form a bond between them which goes beyond physical attraction.

• Complementarity refers to the ways in which a couple provides what each other needs in a relationship i.e. they complement each other (not to be confused with compliment each other which is of course also important for a relationship to thrive - confusing!)
• Complementarity forms the third level of filtering as the potential field of availables has been narrowed down, a relationship may have been established with someone from the field of desirables and it is at this point that each partner asks, ‘Is this relationship working for me?’
• A couple who complement each other will each bring to the relationship something that their partner is not able to bring e.g. Sam does all the cooking, Jen does all the gardening; Brenda is outgoing, Glenda is reserved; Bobby likes to share his problems, Billy is a good listener
• Complementarity, according to Kerckhoff & Davis (1962), is not so important in the early stages of a relationship but is crucial for long-term happiness
• A successful relationship may well depend on complementarity as each person fulfills the needs of their partner which results in a relationship that does not consist of two separate individuals but is instead a whole

Research which investigates filter theory

• Newcomb (1961) - male US students reported that attraction shifted from proximity to those who most closely matched the mens’ attitudes: they began to gravitate towards those who shared similar views to their own as the relationship progressed
• Amodio & Showers (2005) - liking is linked to similarity but this is affected by how committed the relationship is: participants in high-commitment relationships were more likely to favour a similar partner than those in less committed relationships
• Anderson et al. (2003) found that people in relationships become emotionally similar as their relationship progresses (known as emotional convergence) and that couples who are more emotionally similar are more cohesive and less likely to break up which suggests that early similarity and later complementarity may not be as important as previously suggested

Evaluation of filter theory

Strengths

• There is quite a convincing body of research evidence to suggest that filter theory has some validity e.g. Gruber-Baldini et al. (1995) found that social demography is a key determining factor in the first phase of relationship formation
• The theory makes sense, to put it in non-academic terms: people do tend to ‘hook up’ with those from their neighbourhood, home town, college, workplace etc. who share similar attitudes i.e. it has external validity

Weaknesses

• The theory cannot account for relationships which defy the odds as it were: long-distance couples; couples who are diametrically opposed in terms of attitudes; couples who are so alike as to not complement each other; thus it lacks full explanatory power
• There is a lack of temporal validity to filter theory due to the proliferation of online dating and contact via social media channels which means that proximity, for example, is not an issue in relationship formation
  
  

Link to Issues & Debates

Filter theory may suffer from cultural bias as it assumes that people can exercise free will over their choice of partners. While this may be true of individualistic cultures it may not be the case for all collectivist cultures in which families may be involved from the first level of relationship formation and will apply their own filters to their son/daughter’s potential spouse (as occurs with arranged marriages).