Mainstream research portrays prioritization of conjugal relationships over consanguine (i.e., kin) relationships as a standard of adult functioning. However, this “standard” pattern is not a context-general law. Drawing on the Confucian concept of filial piety, we conducted three studies that tested hypothesized mechanisms of cultural-ecological variation in the prioritization of mother versus spouse. Whereas American participants (Studies 1 and 2) prioritized care to spouse over mother in response to an imaginary relationship dilemma, Chinese participants prioritized care to mother over spouse (Study 2). More importantly, residential mobility and filial piety (particularly the authoritarianism component) sequentially predicted participants’ prioritization of mother versus spouse (Study 1 and 2) and mediated the cultural difference in the prioritization (Study 2). In Studies 3A and 3B, we manipulated participants’ sense of mobility and observed consequences for prioritization of care. Prioritization of care to mother over spouse was lower in both Chinese and American settings among participants who imagined living in a mobile environment than among participants who imagined living in a stable environment, and authoritarianism filial piety mediated this effect of the mobility manipulation on prioritization of care. We discuss implications of the research for understanding filial piety across cultural settings and its contribution to a growing body of work on cultural-ecological foundations of love and care.