Harlow’s research studies the importance of nursing in attachment. This was an experiment performed on monkeys. Baby monkeys were removed from their mothers, and placed with two fake, surrogate dummy mothers. One mother was cold, hard, made of plastic and wood, but possessed a bottle full of milk for the baby monkey. The other mother dummy was covered in a heated terry cloth towel. The infants went to the wire monkey for food, but spent an overwhelming amount of time with the towel mother, citing the importance of closeness as comforting rather than just for eating.