Attachment- Harlow monkey study

Harlow's Monkey Study - Aim and Setup

Harlow tested whether baby monkeys prefer comfort or food when forming attachments. He conducted a lab experiment with 8 rhesus monkeys divided into two groups of 4. Each monkey was given two surrogate mothers: one made of wire and one covered in soft towel material. In one group, the wire mother provided milk; in the other group, the cloth mother provided milk. Harlow measured how much time monkeys spent with each mother.

Harlow's Monkey Study - Variables

Independent Variable (IV): Which surrogate mother provided the milk (wire or cloth).

Dependent Variable (DV): The amount of time the baby monkeys spent with each surrogate mother.

Harlow's Monkey Study - Prediction Based on Learning Theory

Learning theory predicts that babies form attachments primarily because the caregiver provides food. Therefore, baby monkeys should prefer the mother who provides milk, regardless of whether she is cloth or wire.

Harlow's Monkey Study - Actual Results

Monkeys spent most of their time clinging to the soft cloth mother, even when the wire mother provided milk. When frightened, monkeys sought comfort from the cloth mother, not the wire mother. This showed that contact comfort, not food, was the key factor in attachment.

Harlow's Monkey Study - Conclusion

Contact comfort is more important than food in the formation of attachment. Monkeys formed an attachment to the soft cloth mother, suggesting emotional comfort drives attachment more than the feeding relationship. This contradicts learning theory.

Harlow's Monkey Study - Strengths

Laboratory experiment allowed careful control over variables (e.g., equal milk supply) ensuring a clear cause-and-effect relationship.

Control of extraneous variables increased reliability of findings.

What developmental issues did Harlow observe in monkeys raised without proper attachment?

Monkeys were socially abnormal, showed aggression, struggled with mating, and were poor parents.

👉 Demonstrates the need for a secure attachment in the critical period (first 30 months) for healthy emotional development.

What are the practical applications of Harlow's research?

Harlow's findings influence the design of zoos and animal shelters, emphasizing the need for:

Attachment figures

Contact comfort

Intellectual stimulation

👉 Supports the development of emotionally healthy animals in captivity.

What were the main ethical issues in Harlow's study?

Monkeys suffered long-term psychological harm—difficulty in social interactions and mating.Harlow likely anticipated the harm.

👉 Raises questions about the ethics vs benefits of psychological research. A cost-benefit analysis is needed to weigh long-term value against ethical breaches.

Harlow's Monkey Study - Weaknesses

The wire and cloth mothers looked different, which could have influenced preference (confounding variable).

Low generalisability: rhesus monkeys are not humans, so results may not fully apply to human attachment.

Ethical issues: monkeys were separated from their real mothers and raised in isolation, causing distress.