Animal studies

• Lorenz's (1935) imprinting study aimed to investigate the mechanism of imprinting where the offspring follow and form an attachment to the first moving object they meet
• Lorenz's (1935) procedure

  • split goose eggs into two batches: one hatched naturally with mother, second batch hatched in an incubator with Lorenz being the first moving object they encountered
  • recorded the gosling's behaviour
  • Marked the goslings based on which hatched with their mother and which hatched in the incubator
  • Both groups were let out together to record their behaviour and measure the effect of imprinting
• Lorenz (1935) found that the goslings who hatched with their mother, followed their mother and those who hatched in the incubator followed Lorenz and showed no interest in their biological mother.
• Lorenz proposed the effects of imprinting are long lasting as he suggested it is irreversible
• Lorenz noticed how the process of imprinting only occurred during a short period of time after birth- the critical period
• Lorenz concluded that imprinting is an innate mechanism which species are biologically programmed to do as soon as they see the first moving object
• Imprinting- innate readiness to develop a strong bond with the mother. Takes place during the first few hours. Imprints on the first moving thing it sees after hatching
• Critical period

  • biologically determined period of time
  • certain characteristics develop that cannot develop outside this period of time
• Sexual imprinting

  • Lorenz (1952)
  • Imprinting will lead to later courtship behaviour
  • observed a peacock that imprinted on a giant tortoise- showed mating behaviour to giant tortoises
• Sexual imprinting affects later mate preferences. Animals choose a mate similar to the species they had imprinted on
• STRENGTHS of Lorenz's study

  • support for imprinting- Guiton (1966) chickens imprinted on yellow rubber gloves that fed them for the first weeks
• LIMITATIONS of Lorenz's study

  • contradictory evidence for imprinting- Guiton et al (1966) found that if animals spend time with their own species, imprinting on objects can be reversed
  • Generalisability to humans- humans are different to birds
• Harlow (1959) aimed to investigate what is more important when forming attachments- food or contact comfort?
• Harlow's study

  • wired mother or soft clothed mother
  • 8 rhesus monkeys were used
  • 2 conditions: wire with milk, clothed with no milk/ wire no milk, clothed with milk
  • observed for 165 days
  • amount of time spent with mothers was recorded
  • frightened with loud noises to test for mother preference when stressed
• Harlow found

  • all monkeys spent more time with the clothed mother- regardless of milk
  • monkeys only spent a small amount of time getting milk from the wire mother, returned quickly to cloth mother
  • stayed with clothed mother when stressed
• Harlow concluded

  • Monkeys have an innate need for contact comfort
  • attachment concerns emotional security more than food
• Long-lasting effects

  • motherless monkeys developed abnormally- both socially (froze and fled) and sexually (no normal mating behaviour)
  • 90 days after, new attachments were impossible and early deprivation became irreversible
• STRENGTHS of Harlow's study

  • theoretical value- shows attachment develops through contact comfort
  • Practical value- Howe (1998) helps social workers understand the risk involved in child neglect and abuse, understand healthy attachment for zoo animals
• LIMITATION of Harlow's study

  • Ethical issues- monkeys suffered distress and isolation, violated guidelines