How diverse are the samples used to study intimate relationships? A systematic review.

The social and behavioral sciences have long suffered from a lack of diversity in the samples used to study a broad array of phenomena. In an attempt to move toward a more contextually-informed approach, multiple subfields have undertaken meta-science studies of the diversity and inclusion of underrepresented groups in their body of literature. The current study is a systematic review of the field of relationship science aimed at examining the state of diversity and inclusion in this field. Relationship-focused papers published in five top relationship science journals from 2014-2018 (N = 559 articles, containing 771 unique studies) were reviewed. Studies were coded for research methods (e.g., sample source, dyadic data, observational data, experimental design) and sample characteristics (e.g., age, education, income, race/ethnicity, sexual orientation). Results indicate that the modal participant in a study of romantic relationships is 30 years old, White, American, middle-class, college educated, and involved in a different-sex, same-race relationship. Additionally, only 74 studies (10%) focused on traditionally underrepresented groups (i.e., non-White, low-income, and/or sexual and gender minorities). Findings underscore the need for greater inclusion of underrepresented groups to ensure the validity and credibility of relationship science. We conclude with general recommendations for the field.