In a study with 291 couples, Shanhong and Klohnen (2003) investigated whether similarity in attitudes and personality has an influence on partner choice or satisfaction with an existing relationship.
Specifically, the following two questions were to be answered:
(1) Are partnerships formed on the basis of mutual similarities?
(2) Does similarity increase satisfaction with an existing relationship?
To answer the first question, the authors compared the similarity of actual couples with randomly formed couples. It was found that actual couples are more similar than random couples with regard to political attitudes, values, and religious beliefs. In contrast, there were also effects of personality on partner choice. Accordingly, people apparently orient themselves in partner choice particularly toward easily communicable and thus easily discernible attitudes and opinions, while similarity in more difficult-to-discern personality traits has no or hardly any influence on partner choice.
To answer the second question, the authors calculated the correlations between the degree of similarity in attitude and personality traits and self-reported as well as externally assessed relationship satisfaction. It was found that similarity in personality traits leads to a significant increase in relationship satisfaction, while similarity in attitudes did not have such a strong effect. Satisfaction with a relationship thus depends, among other things, on the degree of similarity of the personalities of the partners involved. The more similar the personalities, the higher the level of both self-reported and observer-rated relationship satisfaction.
Conclusion:
In partner choice, attitudes play a greater role than personality traits. Satisfaction with a relationship, on the other hand, is determined more by similarity of personalities and less by attitudes. Thus, when there is similarity in both attitudes and personality traits, both good partner choice and long-term relationship satisfaction are promoted.
Shanhong, L., & Klohnen, E. (2005). Assortive Mating and Marital Quality in Newlyweds: A Couple-Centered Approach. Journal of Personality and Social Psychology, 88, 304-326.
