Partner Similarity – Particularly Important in Longer-Term Relationships?
Partner similarity (values, social background, interests …) has a significant impact on relationship quality. This has been repeatedly and reliably demonstrated in numerous studies (see, for example, Shanhong & Klohnen, 2005). Furthermore, it is known that relationship quality has a far-reaching influence on both life satisfaction and health (see the review article by Kiecolt-Glaser & Newton, 2001).
Does the assumption also hold that the importance of similarity increases with the length of the relationship?
In the psychological literature and in our everyday understanding, there is consensus that appearance and social status are primarily important for initiating a relationship. Only at a later stage would similarity—for example, in the form of shared values—become particularly significant. This also means that we might, at “first sight,” choose the wrong partner.
Similarity is considered beneficial because partners misunderstand each other less often and confirm each other more frequently. This leads to a feeling of security and understanding, and ultimately to more enjoyable shared experiences, which then further positively reinforce the relationship. This is especially important in longer-term partnerships. In the long run, incompatible evaluations, expectations, and views are likely only possible with a loss of relationship quality, or can only be resolved through a (necessary) separation.
This connection was recently investigated by psychologists Hermann Brandstätter and Nicole Kornberger. Relationship quality was assessed, for example, with questions such as: “Think about the time you spent with your partner in the last 14 days! Roughly estimate what percentage of that time you felt good!” and “How often in the past 14 days (in relation to your partner) have you experienced the following feelings? (Joy, sadness, anger, disappointment, contempt, compassion, love, sexual satisfaction, jealousy).” The duration of the relationship, as well as value orientations and personality aspects, were also recorded. As expected, it was found that relationship quality with similar values is independent of relationship length. However, if there are significant differences, relationship quality in longer partnerships is very low. To put it pointedly: similarity in values and personality aspects leads people in long-term relationships to feel as much in love as they did on the first day.
Brandstätter, H. & Kronberger, N. (2003). Qualität der Partnerschaft – ein Produkt von Wertkonsens und Beziehungsdauer. Zeitschrift für Sozialpsychologie, 34, 91-106.
Kiecolt-Glaser, J. K. & Newton, T. L. (2001). Marriage and health: his and hers. Psychological Bulletin, 127, 472-503.
Shanhong, L. & Klohnen, E.C. (2005). Assortative mating and marital quality in newlyweds: A couple-centered approach. Journal of Personality and Social Psychology, 88, 304-326.
