A method of behavioral control which utilizes nutritive sucking as the
operant has been evolved in our laboratory. Using this technique we
studied the role of arousal and learning in the development of environ-
mental control over earliest feeding behavior. Few of the infants in our
studies were able to coordinate their sucking behavior to arbitrary
operant-discrimination schedules, but when the individual pattern of
suck- ing was taken into consideration, some infants rapidly adapted to
the reinforcement schedule. Data from various reinforcement schedules
suggest that earliest mothering involves a mutual adaptation in which
the nurturing environment approximates and then entrains the infant's
feeding behavior by a perceptive manipulation of the infant's state of
arousal. Coordination between the infant and its environment sets the
stage for associative learning, which develops following maturation of
the infant's discriminative and response capacities. The process of
behavioral acquisition begins with unconditioned feeding responses,
which are transformed into complex learned behavior through the
mediation of an appropriately reinforcing environment. The infants
studied showed individual differences in susceptibility to environmental
control and in response to frustration. The relative importance of
arousal and learning as determinants of infant behavior are discussed
and a hypothetical model for the earliest mother-infant relationship is
proposed.