As we expand our close relationship (attachment) bonds from parents and caregivers to friends and romantic partners, some of us become more secure while others become more insecure. What determines the direction in which our security deviates? The present study looks at whether self-esteem and worldview systems can account for deviations in security across partners, in both a college sample and a (more generalizable) online sample. Participants who were more secure in their friendships and romantic relationships than in their relationship with their parents/caregivers had higher self-esteem. The impact of worldviews, measured by the extent to which participants used several common belief systems to organize and give meaning to the world, was mixed, such that no one construct was able to account for differences in every relationship, but each contributed to the model in one way or another––perhaps reflective of the heterogeneous nature of worldviews themselves. The results of this study support a theoretical model depicting self-esteem and attachment as overlapping put partly independent sources of psychological support, and point to a need for a general measure of the strength of one’s worldviews that is not tied to specific beliefs.