Final answer:
Harry Harlow is most closely associated with the concept of motherhood, as demonstrated by his experiments on monkeys in the 1950s.
Step-by-step explanation:
Harry Harlow is most closely associated with the concept of motherhood. In the 1950s, Harlow conducted a series of experiments on monkeys, separating them from their mothers and providing them with surrogate mothers made of wire mesh and cloth.
His research showed that the monkeys preferred the soft, cuddly cloth mother, even though she did not provide any nourishment. This experiment challenged the belief that attachment is solely based on nourishment and highlighted the importance of comfort and security in the mother-child bond.