Animal Studies - Harlow

• Why did Harlow conduct the study? 


  • Had been conducting research on learning using monkeys.
  • He noticed when cage was cleaned monkeys became distressed
  • The cages had sanitary pads at the bottom and the monkeys had become attached as a kind of “security blanket”
• Procedure:

  • The cages had sanitary pads at the bottom and the monkeys had become attached as a kind of “security blanket”
  • Therefore Harlow created two wire mothers
  • One had a feeding bottle, the other a soft cloth but no food
  • Monkeys spent most time with the soft cloth mother and would cling to it especially when frightened
• Long lasting effects 


  • continued his research on these monkeys as they grew up to see if maternal deprivation had a permanent effect.
  • They all developed abnormally, even the ones with comfort contact:
  • They froze or fled when approached by other monkeys.
  • They did not show normal mating behaviour
  • They bred less then normal monkey’s (unskilled at mating)
  • As mothers, they neglected their young, some were attacked and even killed by them.
• Conclusion:

  • Like Lorenz, Harlow found there was a critical period.
  • A mother figure had to be introduced within 90 days for an attachment to form.
  • After this time is was impossible, early deprivation is irreversible.
• Weakness - Confounding variables- lacks internal validity

  • The two wired monkeys varied, the heads were different = a confounding variable.
  • Could be said the infant monkeys preferred the head on the cloth monkey.
• Weakness- generalizing animal studies to human behaviour

  • Humans differ in important ways to animals – humans governed by conscious decisions.
  • Schaffer and Emerson (1964) Found infants were not the most attached to the feeder, but too the most responsive who interacted with them most. - Supports comfort rather than food.
• Weakness - ethics


  • long lasting harm as the monkey’s found it difficult to form relationships with peers.
  • However the knowledge from this study outweighs the consequences – benefits outweigh the costs!
• Strength- practical value 


  • helped social workers to understand risk factors in child neglect and abuse
  • therefore, helped to intervene and prevent it.
  • it has helped attachment in zoos and breeding programmes in the wild for animals.