ABSTRACT
This chapter introduces infant smiles and vocalizations also elicit reciprocal responses from adult caregivers, thereby maintaining social interactions. In the nursing relationship, there is usually a regular rhythm of interaction, which may be initiated by either the mother or the infant. In many primates, where mother–infant contact is sustained, initiation of a nursing bout involves relatively minor adjustments. In most mammals, the young are responsible for the initiation of play–bouts with adults. In affluent human societies, the inquisitiveness of the young frequently accounts for parental prohibitions or discipline. Careful observation of interactions between mother caribou and their offspring indicated that 87% of the nursing bouts in which the calf approached the mother from the side or diagonally resulted in maternal acceptance. Bout termination is easy to identify when physical proximity occurs only intermittently. In humans, feedback from the nursing infant affects the termination of feeding bouts.
