Two studies demonstrated the causal role of relationship theories in influencing relationship satisfaction and the processes affecting satisfaction. In both studies, participants were induced to hold either the soulmate or work-it-out theory. Feelings that one's partner was ideal (or not) were associated with relationship satisfaction more strongly for people induced to hold the soulmate theory than the work-it-out theory (Study 1). In Study 2, participants' beliefs about their relationships were threatened, and strategies for responding to this threat were assessed. Inducing people to hold the soulmate theory resulted in more relationship-enhancing cognitions if participants believed they were with the right person but more relationship-detracting cognitions if participants did not believe they were with the right person. These polarizing tendencies were enhanced under threat. In contrast, inducing people to hold a work-it-out theory produced almost no biased processing, leading people to process information similarly, regardless of their feelings about their partner.