The growth of infants' regulatory capacities is foundational to the capacity for resilience. Variations in the quality of early social--emotional experience can promote or undermine infants' regulatory capacities. Such capacities are also dynamically sculpted by the relationships among infant, parent, and contextual--cultural factors. Brief periods of disorganization in parent-infant relationships are inevitable, common, and reflect everyday demands on parents and infants. The uneven nature of parent-infant interactions fosters the emergence of new infant capacities. Parental depression and anxiety as well as infant medical, behavioral, and temperamental issues can result in prolonged periods of dyadic disorganization and maladaptive infant outcomes. Child health clinicians can help parents anticipate the normal periods of disorganization and assist parents as they strive to develop optimal parent-infant relationships.