Harry Harlow's experiment was designed to test the need for affection in growing humans and animals. Two surrogate mothers were designed to test young monkeys that had just been given birth to. A cloth mother who had no food to give the monkeys and a mother made of wire with food for the monkeys were used.
It was found that the monkeys spent most of their time with the cloth mother and only went to the wire mother for food. When left in a room with the cloth mother, they were willing to explore but froze, screamed, and cried when the cloth mother was taken out of the room. This solidified the hypothesis that animals need affection for proper psychological development.
