Harlow contact comfort 1958
Infant monkeys raised with a cloth surrogate and a wire surrogate spent more time clinging to the cloth one even when the wire one supplied the milk.
Main paper: Harlow, H. F. (1958). The nature of love. American Psychologist, 13(12), 673–685. https://psychclassics.yorku.ca/Harlow/love.htm
The question
Is an infant's bond to a caregiver built mainly on feeding, or does comfortable contact matter?
Design: experiment
The researchers set the conditions and compare outcomes between or within groups. Each profile says whether participants were randomly assigned.
The researcher set the conditions by manipulating which surrogate supplied milk and compared infants across arrangements. Groups were very small, and the address describes no random assignment, which limits what can be inferred.
Cloth mother feeds
- Both surrogates present
- Milk from the cloth mother
Result reportedClings to cloth
Wire mother feeds
- Both surrogates present
- Milk from the wire mother
Result reportedStill clings to cloth; visits wire to feed
Original diagram drawn for this site from the descriptions in the sources. It is a simplified summary, not a figure from the paper.
Procedure
Harlow built two artificial mothers: a wire mesh form and a form covered in sponge rubber and terry cloth, each with a heat source. Both could hold a bottle. In the main comparison, eight newborn macaques lived with both. For four the cloth mother supplied milk, and for four the wire mother did. Other infants were raised with a single surrogate or none.
Contact time on each surrogate was recorded automatically. Harlow also tested fear and exploration, for example by presenting a moving toy and placing the infant in an unfamiliar room.
Findings
Infants spent far more time on the cloth mother regardless of which one gave milk. When frightened they ran to the cloth mother and explored more when she was present. After a period of separation they still approached her.
Harlow concluded that contact comfort mattered more than feeding for the infant's attachment.
Interpretation
The results challenged the view that attachment is mainly learned through being fed. Harlow suggested that comfort, contact and other features of caregiving matter, and proposed that the findings might apply to human infants.
Limits on what it shows
- Very small groups of monkeys, and no random assignment described in the address.
- Macaques are not human infants, and cloth surrogates are not caregivers who respond to the infant.
- Rearing without a mother produced unusual development, so behavior may not describe infants in typical conditions.
Ethics
Infant monkeys were separated from their mothers at birth and raised with artificial surrogates. That is a serious welfare cost, and it is the main reason the work is discussed for its methods as well as its findings.
Replication and reassessment
The feeding comparison challenges the claim that attachment is simply learned through milk provision. It does not establish a complete theory of human attachment or justify depriving infants of responsive care. Keep the surrogate comparison separate from Harlow’s later isolation studies.
Think it through. An original practice question written for this site.
Why was it important that the wire mother sometimes supplied the milk?
Show a way to reason about it
If only the cloth mother fed the infants, preference for her could be caused by feeding, comfort or both. Having the wire mother give milk in some groups separates feeding from contact, so a preference for cloth despite no milk points to contact.
Nothing you think or select here is recorded.
Textbook connection
Covered in this sectionOpenStax Psychology 2e, 9.3 Stages of Development
Section describes Harlow's monkey studies.
Sources and access scope
Each label says how much of the source was opened while preparing this profile. An unopened source is listed so the claim can be checked, not because it was read.
- Harlow, H. F. (1958). The nature of love. American Psychologist, 13(12), 673–685. https://psychclassics.yorku.ca/Harlow/love.htmOriginal researchSelected full-text sections inspected
Classics in the History of Psychology reproduction of the presidential address. Setup, groups and results come from sections inspected with page tools.
- Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). Psychology 2e. OpenStax. https://openstax.org/books/psychology-2e/pages/9-3-stages-of-developmentTextbook contextSelected textbook passages inspected
Textbook context. The section describes Harlow's monkey studies.