Courts in seven U.S. states have removed children with “obesity” from parental custody until children could maintain “healthy weights.” These rulings—alongside qualitative reports from parents of children with high weight (PoCHs)—suggest that PoCHs are judged as bad parents. Yet little work has tested whether people genuinely stigmatize PoCHs or what drives this phenomenon. In three experiments with U.S. online community participants ( N = 1,011; two preregistered), we tested an attribution theory model: Social perceivers attribute children’s weights to parents and thus stigmatize those parents. Experiments 1 and 2 support this model (across parent and child gender). Experiment 3 manipulated attributions of parental responsibility for child weight, revealing attenuated stigma with low attributions of responsibility. Findings are among the first to describe and explain stigma toward a large demographic (parents of children with obesity)—with real-world implications (e.g., for family separation, health care)—and may additionally illuminate the psychology underlying stigma toward parents of children with other potentially stigma-evoking identities.

Objective The vast majority of research on biobehavioral influences on development has focused on mothers and infants, whereas research on paternal biobehavioral influences remains sparse. This study aims to increase understanding of paternal influences on the biobehavioral dynamics of the family unit, using a multi-system approach. Methods Participants consisted of 32 predominantly high-risk families recruited during pregnancy who completed monthly questionnaires and in-home visits when infants were 4, 12, and 18 months of age. In-home visits included semi-structured interaction tasks and saliva samples for cortisol and progesterone assays. Results Mothers and infants, but not fathers and infants, showed adrenocortical attunement, with the strongest attunement at 18 months. Second, mothers’ couple satisfaction did not significantly impact infants’ cortisol levels or mother-infant cortisol attunement, but mothers’ progesterone moderated the relationship between couple satisfaction and infant cortisol levels such that mothers with low couple satisfaction, but high progesterone, had infants with lower cortisol levels. Finally, mothers’ and fathers’ progesterone levels were attuned across the time points. Conclusions This is some of the first evidence of the establishment of the family biorhythm and suggests that fathers play an indirect role in facilitating mother-infant adrenocortical attunement. Supplementary Information The online version contains supplementary material available at 10.1007/s40750-023-00215-0.