The development of externalizing behavior in young children is shaped by the complex interaction of temperament, neural mechanisms, and environmental factors. This study explored how child frontal alpha asymmetry (FAA) and child negative affect jointly moderate the relationship between mindful parenting and child externalizing behavior. The sample, drawn from families in the Netherlands, included reports from 128 mothers and 103 partners on mindful parenting, and on children’s negative affect and externalizing behavior. FAA was measured in 95 four-year-old children during an EEG session while they watched an animated video. Results indicated that children with high negative affect and greater left-sided FAA displayed the most externalizing behavior when maternal mindful parenting was low, but the least when mindful parenting was high. In contrast, no significant effects were found for children with lower negative affect or in partner-reported data. These findings suggest that children with both high negative affect and greater left-sided FAA are more sensitive to the quality of mindful parenting, particularly from mothers, aligning with the environmental sensitivity framework. Future research should replicate these findings, ideally in a larger sample, and further examine the long-term, cumulative impact of FAA and negative affect on the development of behavioral problems.

Yarkoni's analysis clearly articulates a number of concerns limiting the generalizability and explanatory power of psychological findings, many of which are compounded in infancy research. ManyBabies addresses these concerns via a radically collaborative, large-scale and open approach to research that is grounded in theory-building, committed to diversification, and focused on understanding sources of variation.

Functional circuits of the human brain emerge and change dramatically over the second half of gestation. It is possible that variation in neural functional system connectivity in utero predicts individual differences in infant behavioral development, but this possibility has yet to be examined. The current study examines the association between fetal sensorimotor brain system functional connectivity and infant postnatal motor ability. Resting-state functional connectivity data was obtained in 96 healthy human fetuses during the second and third trimesters of pregnancy. Infant motor ability was measured 7 months after birth using the Bayley Scales of Infant Development. Increased connectivity between the emerging motor network and regions of the prefrontal cortex, temporal lobes, posterior cingulate, and supplementary motor regions was observed in infants that showed more mature motor functions. In addition, females demonstrated stronger fetal-brain to infant-behavior associations. These observations extend prior longitudinal research back into prenatal brain development and raise exciting new ideas about the advent of risk and the ontogeny of early sex differences.