1. James Houran, Ph.D. on February 16, 2005 8:13 AM writes...

David, thanks for showcasing science on the blog! This article actually reports nothing new, but it does highlight some of the problems in "matchmaking science." First, this study used newlyweds -- which is a tremendous limitation. One needs to study satisfied couples over years -- not just at the beginning of the relationship where positive cognitive biases abound. Second, this study, like most, makes assumptions that new research is showing to be false.

In particular, I have just completed research for presentation at this year's American Psychological Society Conference (and later academic publication) with Rense Lange, Jon Cousins, and Glenn Wilson. It too looked at the notion of “birds of a feather flock together” versus “opposites attract.” The principle of similarity in mate selection currently holds favor in the literature, although an increasing number of studies underscore the merit of a complementarity view. According to the complementarity view, some differences between the partner’s personalities, attitudes, or behaviors may be mutually beneficial in important ways. However, this apparent conflict between the principles of similarity and complementarity may be illusory. Previous research using Item Response Theory (IRT) surprisingly revealed that various personality and behavioral issues are not equal in their relative impact on a couples’ perceived quality of a relationship. Rather, it was found that (i) variables which defined relationship satisfaction formed a hierarchy, and that (ii) men and women differed quantitatively and qualitatively on those relationship variables. These findings suggested that men and women in satisfying long-term relationships agreed on what variables impacted their relationship quality, but that men and women did not have to agree on the relative importance of specific variables to achieve that satisfaction. In other words, relationship satisfaction appears to be grounded in cognitive-behavioral processes, as opposed to being dependent upon patterns of gross similarity or dissimilarity.

The new study aimed to replicate these findings. Applying advanced IRT methods to the data from a recently published study of the responses of 115 UK therapists and their heterosexual partners to the Wilson Relationship Compatibility Indicator (25 items), we found interesting response biases related to gender that highlight the limitations of classical test theory in studying relationship quality (you'll remember that classical test theory was the approach used in the article from the Journal of Personality and Social Psychology). In particular, the basic relationship variables of physique, personality, intelligence, social background, attitudes, habits and leisure preferences significantly predicted scores on the 15-item Locke-Wallace Marital Adjustment Inventory, but these variables formed different hierarchies for the men versus the women. In other words, there were clear gender differences on what makes a satisfying and stability relationship.

Although confirmation with longitudinal studies is necessary, these results cast doubt on simplistic models of relationship quality in terms of gross similarity or complementarity.

Finally, the collaborative effort in this study between two online matchmaking services (CyberSuitors.com and TRUE.com) productively highlights the need for similar companies to adhere to professional testing standards and substantiate their claims of scientifically-based and validated methods. Online dating is growing in societal acceptance as a legitimate approach to mate selection, and compatibility testing appears to be a popular offering among the consumers of these companies. These trends, combined with the advantages of Internet research and advanced IRT methodologies, allow scientifically-oriented relationship services the opportunity to develop increasingly error-free, higher quality matching systems. Beyond the commercial benefits to matchmaking companies and the reputation of cyberpsychology, such efforts are anticipated to offer tremendous clinical and empirical insights for establishing more sophisticated models of mate selection and relationship quality.

Thanks