Sometimes skeptics are tempted to dismiss world beliefs as meaningful phenomena. Such dismissal, we argue, is a mistake. How beliefs about many different broad topics impact behavior is well-established. Psychologically-rich world beliefs have also peppered cultural milieu for centuries. Multiple, decades-old literatures have already established psychometrically the existence of world beliefs, proposed effects, and developed sufficient theory to define the beliefs and explain effects (e.g., Belief in a Just World literature). However, a shared, operationalized list of belief dimensions was lacking. Does one craft such a list a priori, with a specific outcome in mind—the typical approach—or seek to discover pre-existing dimensionality empirically, with no outcome privileged—similar to how Big Five traits were identified? The former being tried (Janoff-Bulman, 1989), Clifton and colleagues (2019) chose the latter, sparking an emerging, interdisciplinary effort. Yet the origins of these beliefs remain unknown and developmental psychologists are, now, sorely needed.