Final answer:
The gentle stroking of the infant's head without the act of nursing that calms the baby is a result of classical conditioning, where a previously neutral stimulus acquires the ability to elicit a conditioned response.
Step-by-step explanation:
In the scenario described, the stroking of the side of the infant's head becomes a calming mechanism. Initially, this action is paired with the act of nursing, a natural source of comfort and nourishment for the baby, which creates a positive association. Over time, simply stroking the side of the baby's head without the act of nursing invokes a similar calming response. This phenomenon can be explained by classical conditioning, a type of learning in which a neutral stimulus becomes associated with a meaningful stimulus and acquires the capacity to elicit a similar response. In this case, the gentle stroking of the baby's head (previously a neutral stimulus) is paired with nursing (a meaningful stimulus that produces a calming effect) until the stroking itself becomes associated with calmness and is able to produce the same effect on its own. This type of conditioned response shows the intricate ways in which infants can learn and adapt to their environments through their well-developed sense of touch and capacity for reflexive behaviors.