filter theory

• Kerckhoff and Davis studied the attitudes and personalities of student couples who had been dating for a short amount of time (less than 18months) or long time. From this they devised the filter theory to explain how relationships are formed and then developed. 
• We have a field of availables: entire set of potential romantic partners with whom we can realistically form a relationship with. Not everyone who is available to us is desirable. 
• 1st level of filter: social demography 

  These are the factors that influence the chances of you meeting. Geographical, social class, ethnicity, religion, level of education. Anyone too different is filtered out which results in homogramy- you are more likely to form a relationship with someone who is culturally and socially similar to you.
• We have three filters to narrow this wide field into our field of desirables
• 2nd level of filter: similarity in attitudes

  Filtered out anyone with different attitudes and beliefs by this level. Early stages of a relationship, partners need to agree over basic values and things that are more important to them. This leads to greater self-disclosure. If partners are dissimilar, it fizzles out. 
• 3rd level of filter: complementary 

  The ability to meet each others needs, one person has traits the other one lacks. Factors are really important for long term relationships, it works because it gives both partners the feelings or ‘the whole’- work together to make a great partnership. 
• A strength of filter theory is that there is research support. Grader-Baldini et al longitudinal study of couples age 21 and found those that were most similar in terms of education level at the start of the relationship were more likely to stay together. This supports the importance of of social demographic factors e.g age and education which is an important aspect of the filter theory. 
• A weakness is that many studies have failed to replicate the findings from the original filter theory study. Levinger suggested that social changes occur over time and there are difficulties in defining ‘depth’ of the relationship. Kerkhoff and Davis chose and 18 month cut of period to distinguish between short and long term relationships and assumed that partners who had been together longer had a more committed and deeper relationship. This highlights problems in attempting to apply filter theory to other couples. 
• One weakness is that the role of filters has changed over time. Filter theory claims that demographic factors reduce the field of available to a relatively small pool of people similar to ourselves. However, the role of filters has changed over time. In terms of the first level filter, online dating and dating apps have increased the field of available so that location no longer limits partners choice. This suggests that filter theory of attraction lack’s temporal validity as it does not account for the changes in dating practices in modern life.