How did Harry Harlow use rhesus monkeys to demonstrate that the attachment theory applied not just to humans but to all mammals? What were the findings of this study?

What will be an ideal response?

Answer: Monkeys were raised with "caregivers" who were just wire shells with faces. In some cases, these "mothers" were covered in a warm cloth; in others, they were just left as wire. The monkeys with the wire mothers had significant social problems. The monkeys with cloth mothers were better adjusted because they derived a sense of security and warmth from the cloth.