animal studies

• Lorenz divided a clutch of goose eggs, one he left in the wild, but the other he hatched in an incubator so the first thing they saw was Lorenz. The incubator group followed Lorenz around but the natural group followed their mother. He concluded there to be a 12-17 hour critical period where they’d imprint on the first moving object seen.
• In a case study, Lorenz (1952) described a peacock who had been reared in the reptile house, where the first moving they saw was a giant tortoise. As an adult, this bird would only direct courtship behaviours to giant tortoises. Lorenz concluded he had undergone sexual imprinting.
• Imprinting - when bird species that are mobile from hatching attach and follow the first moving objects they see
• Critical period - proposed by Lorenz, is the time in which imprinting must occur for attachment to a mother figure
• Attachment of mammals is different to that of birds. Mammals have a greater level of emotional attachment. It is difficult to generalise the findings from geese to human attachment.
• Guiton et al found chickens who had imprinted onto yellow rubber gloves tried to mate with them as adults but eventually, through experience, preferred other chickens. This suggests that the impact of imprinting on mating is not as permanent as Lorenz thought
• the critical period is regarded by some psychologists as more of a sensitive period. Koluchova reported the case study of twin boys who were isolated from 18 months to 7 years. After they were looked after by two loving adults, they appeared to recover fully
• Harlow (1958) used baby rhesus monkeys to observe the importance of contact comfort on development
• In one condition, milk was dispensed by the wire mother and in the second, milk was dispensed by the cloth-covered mother. Harlow found that the baby monkeys sought comfort from the cloth mothers and that they spent more time with the cloth mother over the wire mother regardless of which dispensed milk
• There were severe consequences for maternally deprived monkeys as adults:

  • Ones with only wire mothers were most dysfunctional but both did not develop normal social behaviours
  • More aggressive, less sociable
  • Bred less because they were unskilled at mating
  • As mothers, some of the deprived monkeys neglected their young
  • Others attacked the children, sometimes even killing them
• Harlow showed that attachment does not develop as the result of being fed by a mother figure but as a result of contact comfort
• Harlow also showed the importance of the quality of early relationships for later social development including the ability to hold down adult relationships and successfully rear children
• Harlow's research has helped social workers understand risk factors in child neglect and abuse so intervene to prevent it (Howe 1998).
• Harlow's findings are also important in the care of captive monkeys as we now understand the importance of proper attachment figures for baby monkeys in zoos and also in breeding programmes in the wild.
• Psychologists disagree on the extent to which studies of non-human primates can be generalised to humans
• Harlow faced severe criticism for the ethics of his research
• Harlow referred to the wire mothers as ‘iron maidens’ after the medieval torture device