After briefly reviewing different approaches in the social and behavioral sciences to conceptualize the reasons that humans become motivated to bear children, I present a theoretical framework that incorporates many elements of these approaches. The framework is based on a four-step psychological sequence: the formation of traits, the activation of traits into desires, the translation of desires into intentions, and the implementation of intentions in the form of behavior. I use data from 401 married couples to develop regression models of the two middle steps of this sequence that indicate how childbearing motivational traits lead to childbearing desires and how the latter lead to childbearing intentions. I also develop a regression model that indicates how childbearing motivation affects an individual's perception of his or her spouse's childbearing desires.