Animal studies

• Lorenz investigated imprinting, the process by which bird species that are mobile from birth attach to the first moving thing they see.

  • PROCEDURE: He divided in half a clutch of goose eggs - half were hatched naturally with the mother goose and the other half hatched in an incubator with Lorenz.
  • FINDINGS: Goslings who hatched with Lorenz imprinted on him (followed him). Goslings who hatched naturally imprinted on the mother goose.

  Lorenz also found the goslings had a critical period of 32 hours; if the goslings didn't see a moving object within that time it would loose its ability to imprint.
• Lorenz also investigated adult mate preferences in imprinting.

  
  

  Sexual Imprinting - he observed that birds that imprinted on a human would often later display courtship behaviour towards humans.
• Lorenz's Imprinting Research

  
  

  AO3 Strength: Methodology.

  
  

  The longitudinal study meant the same geese were followed up and observed regularly during their lifetime. This is a strength because it means there were no confounding variables. Internal validity.
• Lorenz's Imprinting Research

  
  

  AO3 Weakness: Generalisability to humans.

  
  

  Humans and birds have different biology and the mammalian attachment system is different from that in birds. This is a weakness because we're ignoring the complexibility of human cognition and physiology compared to animals. Findings cannot be extrapolated.
• Lorenz's Imprinting Research

  
  

  AO3 Weakness: Questionable observations.

  
  

  Guiton found that chickens would imprint on yellow gloves once hatched and later try to mate with it, but with time the chickens learn to prefer to mate with their own kind. This is a weakness because it suggests that effects on sexual imprinting are not as irreversible and permanent as porposed by Lorenz. Lacks reliability.
• Harlow tested the 'Cupboard Love' theory - babies love their mothers because they feed them. He investigated whether rhesus monkeys would show preferences for food or contact comfort.

  
  

  PROCEDURE - 16 baby rhesus monkeys were taken out of their natural environment and placed in cages with 2 model mothers: one made of wire and the other wrapped in soft cloth. In one condition, milk was dispensed in the hard wire mother. In the other condition, milk was dispensed from the soft cloth mother. Time spent with each mother was recorded.
• FINDINGS: Baby monkeys showed preference to the soft mother as they spent 22 hours with it, but when hungry it sought milk from the wire mother.

  
  

  In conclusion, Harlow rejected the cupboard love theory as it was shown that contact comfort is more important and necessary than food.
• Harlow's Monkey Study

  
  

  AO3 Strength: Real-life application.

  
  

  Harlow's study has helped social workers to understand risk factors in abuse cases with children and also used to care for captive monkeys in zoos. This is a strength because it may help to prevent these risk factors in humans and ensure that monkeys have attachment figures. Ecological validity.
• Harlow's Monkey Study

  
  

  AO3 Weakness: Ethical issues.

  
  

  Monkeys suffered high stress levels when removed from their natural environment and the procedure has resulted in long term irreversible effects on the monkeys. This is a weakness because it challenges the BPS's guidelines as they've suffered physicial and psychological harm. Less credibility.