Animal studies

• Lorenz (1935) wanted to test the effect of imprinting on goslings.

  • Do animals always imprint on their mother?
  • How old does imprinting begin?
• Procedure of Lorenz's study

  Lorenz randomly divided the goslings eggs into 2 groups:

  • Left with their natural mother, first thing they saw was their mother
  • Placed in an incubator, first moving object they saw was Lorenz

  The goslings who hatched in the incubator began following Lorenz around.

  Lorenz marked the goslings who had been in the incubator & placed all the goslings together, with Lorenz and their natural mother present
• Findings of Lorenz's study

  The goslings quickly divided; following either Lorenz (if they had been incubated) or their natural mother.

  • those following Lorenz had no recognition of their natural mother
  • The goslings had imprinted on the first moving object they'd seen and became attached

  Lorenz concluded that imprinting happens very early in an infant's life. If an animal does not see a living object within the first 2 days of birth, it will not imprint, imprinting binds a young animal to a caregiver
• Imprinting is when animals form an extremely close attachment with the first moving object they see during the critical period (the first few hours/days after birth).
• Long lasting effects of Lorenz's research

  Imprinting is irreversible/long-lasting.

  early imprinting effects on mate preferences, sexual imprinting. Animals (especially birds) will choose to mate with the same kind of object on which they imprinted
• AO3, imprinting

  Research to support imprinting

  Guiton (1960) found chicks exposed to yellow rubber gloves during feeding in their first few weeks imprinted to the gloves

  • This shows imprinting is innate & they imprint on the first moving object they see within the critical period
  • Guiton found the chicks tried to mate with the rubber gloves when they were older, supporting the idea of sexual imprinting

  This research supports Lorenz's research on imprinting & sexual imprinting, increasing the validity of Lorenz's study
• AO3, imprinting

  Is imprinting actually irreversible?

  Lorenz said imprinting was irreversible, this may not be true

  • Guiton showed that imprinting could be reversed by allowing the chicks in his study to spend time with other chicks. They soon tried to mate with their own species rather than the rubber gloves

  This suggests Lorenz was incorrect and imprinting is actually reversible
• Harlow (1959) aimed to test how an attachment is truly formed, how do baby monkeys form bonds with their mothers?
• What was the procedure of Harlow's experiment?

  Harlow created to wire "mothers", one wrapped in cloth, the other plain wire.

  8 monkeys were studied, 4 were fed by the wire mother, the other 4 by the cloth mother.

  Harlow measured the amount of time each infant spent with their "mothers" and the monkey's response to frightening & new objects

  
• Findings of Harlow's study

  All 8 monkeys spent the most time with the cloth mother, even if they were fed by the wire mother

  • Those fed from the wire mother spent a short time getting milk and then returned to the cloth mother
  • When frightened, all monkeys clung to the cloth mother & when playing with new objects the monkeys stayed close to the cloth mother for reassurance

  Harlow concluded infants develop attachments not to who feeds them, but the person offering comfort
• Long-lasting effects of Harlow's experiment

  The monkeys developed abnormally as they were motherless

  • they were socially abnormal, they froze and fled when approached by other monkeys
  • They were sexually abnormal, did not show normal mating behaviours and did not cradle their own babies

  Harlow found there was a critical period for these effects. Monkeys were able to recover from being motherless if they spent time with other monkeys before they were 3 months old. Having 6+ months with only a wire mother and monkeys could not recover so developed abnormally
• A03, Harlow

  Confounding variables

  The wire mothers varied in more ways than just being cloth covered. The mothers had different heads, the cloth covered one being more attractive & monkey-like, this may be why the monkeys preferred to spend time with it & not the comfort.
• AO3, Harlow

  Generalising animal studies to human behaviour

  Humans behave differently to animals- we make more conscious decisions

  • However, many studies note animal attachments are mirrored in human attachments e.g Schaffer and Emerson's study supports Harlow's research

  Arguably, animal studies are still useful for explaining human attachments