Animal Studies

• What is imprinting?


  A rapid learning process that takes place early in the life of a social animal (such as a goose) and establishes a behaviour pattern (such as recognition and attraction to its own kind or a substitute)
• Animal studies are carried out for:

  • Practicality- animals breed faster; researchers want to see results across multiple generations of animals
  • Ethicality- research can be carried out on animals that is not allowed on humans due to ethical implication
• Lorenz claimed learning processes depend on:

  • Innate knowledge
  • Learning from individual experiences
• Lorenz (1935):

  Aim: investigate mechanisms of imprinting where some species of animals form an attachment to the first large moving object they meet (suggesting attachment is innate and programmed genetically)

  Method: Condition 1- eggs with mother & hatched with mother, 2- eggs in incubator & hatched with Lorenz; once hatched, goslings mixed up and observed who they followed.
• Lorenz (1935):

  Results: C1- followed mother, C2- followed Lorenz

  Lorenz varied time between hatching and seeing a moving object to measure the critical period for imprinting:

  Goslings follow the first moving object between 13-16 hours after hatching

  Conclusion: goslings have a biological propensity to form attachments to one single object. Supports view of biological basis for attachment is adaptive, promoting survival
• Sexual imprinting (Lorenz):

  Goslings that imprinted on humans displayed courtships behaviour towards humans.

  Lorenz described a peacock reared in the reptile house of a zoo, seeing tortoises as the first large moving object. As an adult, the peacock only directed courtship behaviour to tortoises- sexual imprinting.

  Lorenz found same behaviour with goslings imprinting on yellow plastic gloves
• Implications of animal studies of attachment (Lorenz, 1953):

  1. Goslings imprinted irreversibly so early in life: critical period is biologically determined
  2. Longevity of goslings' bond with Lorenz supports view that early attachment experiences predict future bonds
  3. Powerful instinctive behaviour displayed suggests attachments are biologically programmed into species according to adaptive pressures
  4. Imprinting is key in learning social behaviours
• W- Extrapolation (Lorenz):

  Humans and animals are psychologically different. The way a human infant develops and attaches to primary caregiver may be different to that of goslings. For example, mammals show more emotional reactions to their babies compared to birds; mammals are able to form attachments beyond the first few hours after birth
• W- Contradicting research (Lorenz):

  Guiton et al. found that chickens would imprint on yellow washing up gloves if that was the large moving object they saw after hatching and they would then try to mate with that object in adulthood.

  However, Guiton et al. disagreed with Lorenz's prediction that this relationship persists and is irreversible; with experience, chickens could eventually learn to prefer mating with other chicken instead suggesting the effects of imprinting may not be as permanent as initially thought
• Harlow (1958):

  Aim: to find if monkeys attach to their mothers because they feed them or because they provide a safe environment

  Method: 16 rhesus monkeys caged from infancy with wire mesh and cloth, covered surrogate mothers (IV- type of mother; DV- amount of time spent with each surrogate mother + time spent crying for biological mother); C1- wire mother dispensing milk, cloth mother with NO milk, C2- wire mother with NO milk, cloth mother dispensing milk, C3- wire mother dispensing milk, C4- cloth mother dispensing milk
• Harlow (1958):

  Results: when given a choice of surrogate mother, baby monkey prefer to make contact with cloth mother whether she is dispensing milk or not; monkeys would stretch across to wire mother to get food while clinging to cloth mother for contact/ comfort.

  Monkeys with only wire mother showed signs of stress like diarrhoea

  When startled by loud noises, baby monkeys would cling to cloth mother if available

  Greater exploration behaviour seen in baby monkeys with cloth mother- emotional security
• Harlow (1958):

  Conclusion: baby monkeys have innate drive to seek contact and comfort from parents suggesting attachment formation through emotional need for security rather than food (contradicting learning theory)

  Contact with mother associated with higher willingness to explore surroundings and lower stress levels
• Maternal deprivation in monkeys as adults:

  Isolated monkeys failed to develop functional social behaviour, suggesting animals have greater needs than food

  Harlow found monkeys reared with wire mothers only were the most DYSFUNCTIONAL- even those reared with soft toy did not develop normal social behaviour; less sociable, more aggressive and less likely to mate

  Adult female monkeys neglected their babies, some attacked their children, even killing them in some cases
• W- Unethical (Harlow):

  Monkeys showed great distress when removed from biological mothers. After the study, monkeys placed with other monkeys and showed great distress in social situation/ unable to communicate. When studied monkeys had children, they neglected their offspring. Study breaches BPS guidelines as monkeys were not protected from harm.

  Study does not tell us anything about formation of human attachments as monkeys and humans are psychologically different. Psychologists argue lack of generalisability makes it even more unethical and unjustifiable
• S- Controlled laboratory setting (Harlow):

  Potential extraneous variables were controlled like monkeys being taken away from their mothers immediately after birth; no exposure to love/ affection from biological mother. Harlow measured what he intended (factors affecting formation of attachment); study is seen to have high internal validity and allowing a cause-effect relationship to be established