Recruitment and selection of couples for intervention research: achieving developmental homogeneity at the cost of demographic diversity.

Demographic and relationship quality data were collected from 704 individuals recruited to participate in a randomized study of relationship enhancing interventions. Recruiting at bridal shows produced partners who were more satisfied, earlier in their relationships, and less likely to be parents, with a marginally higher proportion of Latino couples. Radio and television coverage produced more established couples with higher levels of relationship discord. Self-selection effects revealed that couples from demographic groups at greater risk for divorce (those who had not completed high school, those with children at marriage, and African American couples) were more likely to agree to participate. In contrast, imposing a set of common selection criteria served to exclude couples from demographic risk groups and selected for couples with higher marital quality. Implications for recruiting couples to participate in preventive interventions are outlined.