Partner similarity matters for the insecure: Attachment orientations moderate the association between similarity in partners' personality traits and relationship satisfaction

A longitudinal sample of romantic couples was used to examine whether attachment security moderates the association between partners' personality-trait-similarity to each other and their relationship satisfaction. Replicating previous research, there were no bivariate associations between trait-similarity and satisfaction. However, partners' perceptions of personality-similarity were associated with satisfaction. Attachment styles also moderated the curvilinear associations between partners' trait-similarity and satisfaction. People with high attachment avoidance and low attachment anxiety (dismissing attachment) seemed to have an optimal level of similarity in which satisfaction was maximized at moderate levels of similarity. People with low avoidance and high anxiety (preoccupied attachment) exhibited the opposite pattern, expressing higher levels of satisfaction if their partner was highly similar or dissimilar to them.