Conventional wisdom views the parent-child relationship as unilateral: Parents' actions upstream flow downstream to shape their children's development. However, scholars have proposed that this view of parenting is lopsided; children may influence their parents no less than parents influence children. We apply this bilateral perspective in a reexamination of the robust finding that confident people report having had more supportive parents. The social-cognitive explanation for this finding is that parents endow their children with support that builds confidence. However, evolutionary accounts suggest that confident children-displaying more promise and potential-ought to attract their parents' investments of support. We examined these predictions in a four-wave longitudinal study drawing on both archival and field survey data from 350 STEM students (science, technology, engineering, and mathematics) in the Philippines. Results were consistent with the bilateral perspective, in which parental support endowed children with confidence, but also children's confidence attracted parental support in equal measure. These reciprocal relations also had implications for whether or not students persisted in their computer science degrees. The results indicate that parental endowments of confidence and parental investments of support form a virtuous cycle, consistent with the perspective that self-efficacy operates not only as an intrapsychic resource allocator but also as an interpersonal resource attractor. (PsycInfo Database Record (c) 2021 APA, all rights reserved).