Final answer:
Harry Harlow's research showed that social comfort and security are crucial for infant attachment to mothers, influencing subsequent theories and research in the field of developmental psychology.
Step-by-step explanation:
The research of Harry Harlow demonstrated that social comfort and feelings of security were the basis for the attachment of infants to their mothers. Harlow's experiments with rhesus monkeys in the 1950s revealed that the monkeys preferred a soft, cloth surrogate mother that provided comfort over a wire mesh mother that provided nourishment, overturning previous beliefs that attachment was based solely on fulfilling nutritional needs. Building on these findings, John Bowlby developed attachment theory, emphasizing the importance of a secure base and responsive caregiving for healthy social and emotional development.
Further research by Mary Ainsworth through the Strange Situation procedure identified different patterns of attachment, with secure attachment being the most healthy. It reaffirmed the importance of caregiver sensitivity and responsiveness to an infant's needs. Bowlby, Harlow, and Ainsworth's research collectively underscored the critical role of emotional bonds and caregiver interactions in the development of attachment.