Describe and evaluate the filter theory of romantic relationships

1) Filter theory – Kerckhoff & Davis

We narrow the “field of availables” to a “field of desirables” using 3 filters: social demography, similarity in attitudes, and complementarity of needs.

2) Social demography (Filter 1)

Includes proximity, education, class, and religion. People tend to form relationships with those physically and socially similar — less effort needed.

Similarity in attitudes (Filter 2)

Shared values promote communication and attraction in early stages. Dissimilar partners are filtered out as the relationship is less likely to last.

Kerckhoff & Davis – attitude findings

Found similarity in attitudes was a strong predictor of relationship success in couples under 18 months — supports early filtering.

Complementarity (Filter 3)

Partners meet each other’s needs through differences — e.g., one nurtures, one is dependent. In long-term, opposites may attract.

6) Example – older/younger attraction

A younger woman may value an older man’s stability, while he values her youth — shows complementarity supports long-term bonds.

✅ Research support – complementarity + similarity

Winch found similarity important early on, but complementarity mattered later — supports stages of filtering.

✅Gruber-Baldini – longitudinal support

Found couples with similar age/education more likely to stay together — supports filter theory’s focus on sociodemographic factors.

❌Temporal validity issue

Dating apps reduce importance of proximity — people now meet outside their social group. Filter theory may be outdated.

❌Correlational limitation

Most studies show links, not cause-effect. Similarity may not cause success — could be that closeness increases perceived similarity.