Harlow’s classic experiment involving rhesus monkeys.

Harlow removed young monkeys from their natural mothers a few hours after birth and left them to be “raised” by these mother surrogates. The experiment demonstrated that the baby monkeys spent significantly more time with their cloth mother than with their wire mother. “These data make it obvious that contact comfort is a variable of overwhelming importance in the development of affectional response, whereas lactation is a variable of negligible importance,” Harlow explained (1958).
Harlow’s classic experiment involving rhesus monkeys.

Harlow removed young monkeys from their natural mothers a few hours after birth and left them to be “raised” by these mother surrogates. The experiment demonstrated that the baby monkeys spent significantly more time with their cloth mother than with their wire mother. “These data make it obvious that contact comfort is a variable of overwhelming importance in the development of affectional response, whereas lactation is a variable of negligible importance,” Harlow explained (1958).