Final answer:
Harry Harlow's monkey experiments highlighted the central role of social comfort over nourishment in the formation of attachment, influencing the field of psychology and the understanding of child development.
Step-by-step explanation:
Psychologist Harry Harlow's experiments with monkeys have significantly advanced our understanding of the importance of attachment in psychosocial development. Harlow's research in the 1950s and 1960s involved newborn monkeys that were provided two surrogate mothers; one was made of wire mesh and could dispense milk, while the other was a softer surrogate made of cloth but did not provide food.
The experiments revealed that the monkeys formed a stronger bond with the soft, cloth surrogate, preferring its comfort over the wire surrogate that provided nourishment, suggesting that the need for social comfort and security is more crucial to attachment than previously thought.