Harlow's baby monkey study

• Aim: to test whether attachments are primarily formed through food as explained by the learning theory or whether attachment concerns emotional security
• Procedure:

  • constructed two types of surrogate mother
  • 'wire mother' and 'cloth mother'
  • 8 infant monkeys studied for 165 days
  • half monkeys had the milk bottle on cloth mother, other half had milk bottle on wire mother
  • Harlow recorded time spent with each mother
  • Made monkeys afraid in order to test for mother preference
• Harlow's Findings:

  • All monkeys spent more time with the cloth mother, whether or not the cloth mother had the milk
  • when frightened all monkeys went to the cloth mother
  • the monkeys didn't develop normally (e.g. froze or fled when approached by other monkeys, did not show warmth towards their own babies)
  • Critical period - monkeys could not recover from spending more than 6 months with only the wire mother
• Harlow's conclusions:

  • Attachment concerns emotional security rather than food as infant monkeys attach to the mother who offered comfort, not food.
  • Experiences in infancy have an effect on later life as monkeys had problems with relationships
• Limitation: it is not possible to extrapolate from animals to humans as humans have more complex attachments than monkeys. However, unlike in Lorenz's study, monkeys are closer to humans than geese, so extrapolation may be possible.
• Limitation: the study may be considered unethical as it involves the separation of the baby monkeys. The separation caused considerable stress and later psychological harm meant that they then couldn't form relationships. Therefore, the unethical nature of the experiment may be classed as unjustifiable.
• Strength: however, the research during Harlow's study may be justifiable as it influenced Bowlby to develop the maternal deprivation hypothesis. This means that as Harlow's research was useful to later researchers, it may justify the unethical nature of the experiment.