Animal Studies: Lorenz and Harlow

• What did Lorenz and Harlow study?

  • Lorenz = imprinting
  • Harlow = contact comfort and maternal-separation
• What was Lorenz aim?

  Looking into imprinting
• What was Lorenz's procedure?

  Divided a clutch of eggs into 2: some hatched with their mother (control group) and others hatched in an incubator where they first saw Lorenz. The control group followed round their mother as expected, but the 2nd group followed round Lorenz. Even when the 2 groups were mixed together, they all went to their ‘mother figure’.
• What was Lorenz's findings?

  Discovered the critical period (12 hours for birds) where an attachment must be formed – if not, it may never be formed. Imprinting is irreversible and long-lasting.
• Additional info for Lorenz

  Sexual imprinting - He found that imprinting has an effect on later mating preferences. E.g., he raised a peacock in a reptile house, where it attached to a tortoise – in later life, the peacock showed courtship to tortoises
• What was a strength of Lorenz's study?

  Research support

  • Regolin et al exposed chicks to simple shape-combinations that move, and the chicks showed preference to the moving shapes (young animals are born with an innate mechanism to imprint)
• What was Harlow's aim?

  Investigate the importance of contact comfort vs food comfort
• What was Harlow's procedure?

  A group of monkeys were separated from their mothers at birth and placed in cages with 2 surrogate mothers: a wire mother and a cloth mother. Half the monkeys could get milk for the wire mothers and the other half could get milk from the cloth mother.
• What was Harlow's findings?

  Both groups spent more time with the cloth mother. The infant would only go to the wire mother when it was hungry. Therefore, contact comfort is more important than food comfort.
• Additional info about Harlow:

  Maternal deprivation - Found that monkeys who were maternally deprived were timid, easily bullied and had difficulty mating. These behaviours were only found in monkeys who were alone for over 90 days – 90-day critical period
• What is a strength of Harlow's study?

  Research has informed human attachment

  • Research showed maternal deprivation affected monkeys into adulthood, which is similar for humans (IQ lower and slow emotional development)
• What is another strength of Lorenz's study?

  Research has informed human attachment

  • 'Baby duck syndrome’ is where computer users become attached to their first computer = imprinting is meaningful
• What is a limitation of Lorenz's study?

  Cannot generalise human behaviour to birds

  • (mammalian attachment system is much more complex than birds - more emotional attachment)
• What is another strength of Harlow's study?

  Practical applications

  • Helps us understand the urgency for helping orphaned/abandoned babies (90 critical period)
• What is a limitation of Harlow's study?

  Cannot generalise human behaviour to monkeys

  • (although behaviourist approach says animals are like humans, we know this isn't true)
• What is another limitation of Harlow's study?

  Ethical issues

  • Caused long-term distress to the monkeys