Animal Studies on Attachment

• Describe Lorenz's research

  • Investigated imprinting
  • Set up a classic experiment where he randomly divided a large clutch of goose eggs. Half of the eggs were hatched with the mother goose in their natural environment, while the other half were hatched in an incubator where the first moving thing they saw was Lorenz
• What did Lorenz find?

  • The incubator group followed Lorenz everywhere, while the control group followed the mother
  • When the two groups were mixed up, the experimental group still followed Lorenz and the control group continued to follow the mother
• What did Lorenz conclude?

  • Lorenz identified a critical period where imprinting needs to take place. Depending on the species, this could be as little a a few hours after hatching.
  • If imprinting did not occur within the critical period, the chicks would not attach themselves to the mother figure
• What is imprinting?

  • Where offspring follow the first moving thing they see
• What is a critical period?

  • A period of time in which an event must happen for it to have an effect
• What is sexual imprinting?

  • Lorenz observed that birds that imprinted on a human would often later display courtship behaviour towards humans
  • In a case study, Lorenz described a peacock that had been reared in a zoo's reptile house where the first moving objects the peacock saw were giant tortoises.
  • As an adult, this bird would direct courtship behaviour towards giant tortoises (it had undergone sexual imprinting)
• What did Harlow research?

  • Attachment in rhesus monkeys (which are more similar to humans than birds)
• Describe Harlow's procedure

  • Tested if soft objects serve the same functions as a mother
  • He reared 16 baby monkeys with two wire model monkeys
  • One model was soft and disposed no milk, while the other wasn't soft but disposed milk
  • The monkeys spent more time with the soft cloth mother, despite it not dispensing any milk. This shows how contact comfort was more important to the monkeys than food
• What did Harlow find happen to the monkeys with no mother figure?

  • When followed into adulthood, the researcher found that early maternal deprivation had a severe effect on the monkeys
  • The monkeys reared with only wired mothers were most dysfunctional. They were more aggressive, less sociable and bred less often than normal. Some monkeys even neglected their young or killed them. But those with a cloth mother also didn't grow up to be normal
• What did Harlow find was the critical period for development?

  • A mother figure had to be introduced to an infant monkey within 90 days for an attachment to form
  • After this time, attachment was impossible and damage done by early deprivation became irreversible
• What are benefits of animal studies into attachment?

  • Lorenz's research has supporting evidence for imprinting
  • Harlow's research has high practical and theoretical value
• What evidence is there to support imprinting?

  • Researchers exposed chicks to simple shape combinations that moved, (i.e. a triangle with a rectangle front). A range of shape combinations were moved in front of them, and they followed the original most closely, suggesting they built an attachment to that shape.
  • This supports that animals are born with an innate mechanism to imprint on a moving object present in a critical period of development, as predicted by Lorenz
• How does Harlow's research have good theoretical and practical value?

  • His findings have a profound effect on psychologists' understanding of mother-infant attachment
  • Harlow showed attachment is based on comfort and security, not food. It also helped social workers and clinical psychologists understand that a lack of bonding experience may be a risk factor for child development, allowing them to intervene to prevent poor outcomes.
  • We also understand the importance of attachment figures for baby monkeys in zoos and breeding programmes
• What issues are there with animal studies into attachment?

  • Harlow's experiment has ethical issues
  • Lorenz's research has poor generalisability to humans
• What ethical issues does Harlow's experiment have?

  • The animals were not protected from psychological harm
  • They were harmed in the short term and long term as they grew up to be aggressive and have difficulty forming attachments in the future. This gives psychology a bad reputation.
• What is a counter to Harlow's research having ethical issues?

  • His research was groundbreaking and allowed us to learn more about attachment and the effects of maternal deprivation
  • It is also a lot more ethical than using human babies
• Why does Lorenz's research have poor generalisability?

  • He investigated imprinting on birds. It is unlikely that the observation of goslings following a researcher reflects the emotional connections and interaction that characterises human attachments.
  • In mammals, attachment is a two way process; both mothers and young need to have an emotional attachment to each other
  • This means that it might not be appropriate to apply the concept on imprinting to humans