Psychology › Development & attachment › Attachment theory (John Bowlby)
Harlow's monkeys: comfort over food
1958· Finding or experiment
Well replicatedStrong, repeated evidence.
Infant monkeys preferred a soft cloth 'mother' without food to a wire one with milk, showing comfort matters beyond feeding.
See it on the Psychology map →What it says
At the University of Wisconsin, Harry Harlow separated infant rhesus monkeys from their mothers and gave them two artificial ones: bare wire holding a milk bottle, and soft cloth with no food. The infants spent up to about 18 hours a day clinging to the cloth figure, visited the wire one mainly to feed, and ran to the cloth one when frightened. Monkeys raised in isolation later struggled to socialize and to care for their own young.
Why it matters
It overturned the idea that babies love whoever feeds them. Contact comfort became recognized as a basic need, influencing orphan care, hospital practice and skin-to-skin contact for newborns.
The evidence
Status: well replicated. Harlow's 1958 report and films, later primate studies, and studies of children in severely neglectful orphanages all show lasting effects of early deprivation of comfort and care.
Open questions
Whether the knowledge justified the animals' suffering; the experiments are now widely viewed as cruel and helped spur stronger animal-research protections.
Connections (2)
▸Harlow's monkeys: comfort over food contradicted the feeding account of BehaviorismWell replicated
The connection
Behaviorists, and many psychoanalysts too, held that babies love their mothers because mothers feed them: affection was a learned by-product of reward. Harlow's infant monkeys clung to a soft cloth figure that gave no milk and visited the wire one mainly to drink. Comfort itself was a basic need, not just a conditioned reward.
Who showed it and when
University of Wisconsin–Madison primate lab; announced in Harlow's 1958 American Psychological Association presidential address, 'The Nature of Love'.
The evidence
Harlow logged hours spent on each surrogate, up to about 18 a day on the cloth one. John Watson's 1928 child-care book, warning against cuddling, shows the view Harlow overturned.
Open questions
Whether learning theory was refuted or just revised; later learning theorists folded 'contact comfort' in as a reward of its own.
▸Harlow's monkeys: comfort over food supported Attachment theory (John Bowlby)Well replicated
The connection
Bowlby argued babies are built to seek closeness and comfort, not just food. Harlow's monkeys gave him animal evidence: they bonded with a soft cloth figure, ran to it when frightened, and used it as a safe base for exploring new rooms. Monkeys raised without any mother grew up with lasting social problems.
Who showed it and when
Wisconsin, from 1958; Bowlby and Harlow corresponded and met, and Bowlby cited Harlow's results in Attachment (1969).
The evidence
Harlow's published experiments and films, Bowlby's citations, and their contacts documented in Deborah Blum's 2002 history Love at Goon Park.
Open questions
How far findings on caged monkeys apply to human babies, and whether such distressing experiments were justified; many scientists today say no.