Thinking about moving in together? Reasons for cohabitation are associated with relationship outcomes over time.

Romantic couples moving in together (i.e., cohabitation) is a normative stage of romantic relationships, and people report different reasons for moving in together. Few studies have examined whether reasons for cohabitation have implications for relationship functioning over time. This study investigated how three commonly endorsed reasons for cohabitation (i.e., to spend time together, to test the relationship, and out of convenience) were associated with relationship outcomes (relationship functioning and dissolution) over time. In a five-year longitudinal study (from 2007 to 2012), adults (<i>N</i>=485) who were in opposite-sex relationships and moved in with their partner were surveyed on their reasons for cohabitation (closest in time to moving in together), and their relationship status and functioning (in up to 11 waves of surveys). Results showed that greater endorsement of cohabiting to spend time together predicted better overall relationship functioning after cohabiting. Greater endorsement of testing the relationship predicted worse overall relationship functioning and a higher likelihood of relationship dissolution after cohabiting. Moving in together out of convenience did not predict post-cohabitation relationship outcomes. The three reasons did not predict over-time trajectories (i.e., slopes) of relationship functioning. Instead, people showed similar trajectories of relationship functioning after moving in together regardless of their reasons for cohabitation, albeit at different levels that were differentiated at the time of moving in together. Reasons for cohabitation appear to reflect pre-existing relationship quality, instead of impacting its post-cohabitation trajectories. Findings highlight the importance of couples discussing their reasons for cohabitation when making decisions about moving in together.