Animal studies: Harlow

• Harlow’s monkeys

  Harlow conducted one of the, now, most famous and influential psychological animal studies to date. 

  One of the biggest criticisms of Lorenz’ research with geese is that it was not generalisable to humans. Geese and lots of birds imprint upon sight for evolutionary benefit, however we know that this is not the case for humans. 

  Harlow’s research was so influential because he used Rhesus monkeys which are very similar to humans

  AND the findings were unexpected
• AO1 - Aim & method

  Harlow observed that newborn monkeys would often die if kept in cages alone. However if they were given something soft to cuddle, they would be more likely to survive.

  Harlow tested the hypothesis that the soft object served some of the functions of the mother. 

  He reared 16 baby Rhesus monkeys with the option of two wire ‘mothers’ - a cloth mother and a wire mother.
• In one condition the cloth mother dispensed milk and in the other the wire mother dispensed milk.
• AO1 - Findings

  The baby monkeys unanimously preferred to cloth mother and cuddled ‘her’ in preference to the wire mother. 

  The monkeys would also seek comfort from the cloth mother when frightened regardless of which mother dispensed milk.

  Most notably the baby monkeys would sometimes remain in contact with the cloth mother whilst feeding from the wire mother.
• AO1 - Conclusions

  Harlow concluded that contact comfort was more important than food in the formation of attachment.

  They became most attached to the cloth mother, but never formed a real attachment
• What was the main focus of Harlow's study on maternal deprivation?


  To investigate the effects of maternal deprivation on monkeys into adulthood
• What were the findings regarding monkeys deprived of a real mother?


  They exhibited severe consequences and dysfunctionality
• How did the monkeys reared with just the wire mother compare to those with a soft toy substitute?


  Monkeys with the wire mother were the most dysfunctional, but those with a soft toy also did not develop normal social behavior
• What behavioral traits were observed in the deprived monkeys?


  They were more aggressive and less sociable than other monkeys
• How often did the deprived monkeys breed compared to common rates?


  They bred less often than is common
• What skills were the deprived monkeys unskilled at?


  They were unskilled at mating
• What maternal behaviors were observed in the deprived monkeys when they became mothers?


  They neglected their young and some attacked their children
• What extreme behavior was noted among some deprived monkeys towards their children?


  Some even killed their children
• AO1 - Establishing a critical period

  QUICK FIRE RETRIEVAL - What was the critical period Lorenz established for the geese?

  A few hours! (depending on the breed)

  Harlow’s critical period was much longer. He found that a mother figure had to be introduced to the monkey within 90 days for an attachment to form. 

  If this did not happen an attachment would never form and the damage would be irreversible.
• AO3 - Evaluation

  (+) Theoretical value

  Harlow’s findings had an influential effect on psychologists understanding of human-infant attachment. Most importantly, Harlow showed that attachment does not develop as the result of being fed by a mother figure but as a result of contact comfort. Harlow also showed the importance of the quality of early relationships for later social development.
• AO3 - Evaluation

  (+) Practical value

  The insight from Harlow’s research has had important applications in a range of practical contexts.

   For example, it has helped social workers understand risk factors in child neglect and abuse and so intervene to prevent it.
• What ethical issues were associated with Harlow's research?


  Harlow faced severe criticism for the ethics of his research.
• What lasting impact did Harlow's study have on the monkeys involved?


  The study created lasting emotional harm, making it difficult for the monkeys to form relationships with their peers.
• What justification is provided for Harlow's experiment despite ethical concerns?


  • Significant effect on understanding attachment processes
  • Research has improved care for human and primate infants
• Why is it difficult to generalize Harlow's findings to humans?


  It is difficult to generalize from animals to humans.
• Which study's findings have supported Harlow's research?


  Studies by Schaffer & Emerson have supported Harlow's research.