Classical conditioning - Before attachment is learned, the infant gains pleasure through being fed. Food is the unconditioned stimulus and pleasure is the unconditioned response. When the infant is being fed, the infant associates the person providing the food with the food. The primary caregiver is the neutral stimulus, which becomes associated with food (the unconditioned stimulus). When the attachment has been learned, the infant gains pleasure when the primary caregiver is present. The primary caregiver is now the conditioned stimulus and pleasure is now the conditioned response.
Operant conditioning - When an infant is hungry it is in an uncomfortable state. Relieving the uncomfortable state will make the infant more comfortable, and so anything it does to make itself more comfortable will be learned through negative reinforcement. A hungry baby will cry because it is distressed. Feeding the baby makes it more comfortable and so crying is learned through negative reinforcement. Over time the pleasure of being made comfortable by being fed becomes associated with the primary caregiver. The baby has now learned to cry to get the primary caregiver’s attention, and it feels pleasure when the primary caregiver is present. Attachment has now been learned.
Learning theory provides a very reliable explanation for attachment formation. It seems highly likely that simple association between the provision of needs essential for survival and the person providing those needs can lead to strong attachments. However the theory is questionable and there is evidence that infants can form attachments with a person who is not the primary care-giver.
Harlow (1958) experimented with the attachments formed between rhesus monkeys and surrogate mothers. In this case the surrogate mothers were wire framed models that provided food and therefore satisfied the monkeys' primary needs, or ones that...