3.2 Animal Studies

3.2 Animal Studies

1. Harlow - Effects of Privation (1958). Harlow wanted to study the mechanisms by which newborn rhesus monkeys bond with their mothers. The behavioural theory of attachment would suggest that an infant would form an attachment with a carer that provides food.

   • In contrast Harlow's explanation was that attachment develops as a result of the mother providing "tactile comfort", suggesting that infants have an innate (biological) need to touch and cling to something for emotional comfort.
   • Procedure - 16 monkeys were separated from their mothers immediately after birth and placed in cages with access to two surrogate mothers, one made of wire and one covered in soft towelling cloth. Eight of the monkeys could get milk from the wire mother. The other eight could get milk from the cloth mother
   • Results: Both groups of monkeys spent more time with the cloth mother, even if she had no milk. The infants of the second group would only go to the wire mother when hungry. Once fed they would return to the cloth mother for most of the day. If a frightening object was placed in the cage the infant took refuge with the cloth mother. The infant would explore more when the cloth mother was present. Then Harlow observed the differences in behaviour between the monkeys who had grown up with the surrogate mothers and those with normal mothers. They found that: they were much more timid, they didn't know how to act with other monkeys, they were easily bullied and wouldn't stand up for themselves, they had difficulty mating and the females were inadequate mothers. These behaviours were observed in the monkeys who were left with the surrogate mothers for more than 90 days.
     • For those left less than 90 days the effects could be reversed if placed in a normal environment where they could form attachments.
   • Conclusions
     • Harlow concluded that 'contact comfort' which was provided by the cloth mother was more important than food in the formation of attachment
     • He also concluded that early maternal deprivation leads to emotional damage but hat its impact could be reversed in monkeys if an attachment was made before the end of the critical period
       • Therefore more social deprivation than maternal deprivation
   • Evaluation
     • Distress caused to monkeys as they were deprived of their mother from birth and placed into cages
       • However the benefit of this study outweighs the cost
     • Monkeys suffered emotional and psychological damage
       • Offspring of the studied monkeys were subjected to abuse by their incapable mothers, some mothers even smashed their babies head
     • Extrapolation issues

2. Lorenz - Imprinting (1935) took a large clutch of goose eggs and kept them until they were about to hatch. Hal of the eggs were placed under a goose mother, while Lorenz kept the other half in an incubator beside himself. When the geese hatched Lorenz imitated a mother duck's quacking sound, upon which the young birds egarded him as their mother and followed him accordingly. The other group (control group) followed the mother goose.

   • Results: The control group followed the goose mother whereas the second group followed Lorenz. He even marked the goslings to indicate which groups of eggs they had hatched from and then let them out together from an upturned box: each goslings went to its 'mother figure'. Lorenz' goslings showed no recognition to their real mother
   • Supports nature in the 'nurture vs nature' debate as the goslings were not taught to Lorenz, however had the innate tendency to attach to him. (evolutionary)
   • Lorenz discovered a critical period; a time period where an attachment must be formed or no attachment will be formed at all. Lorenz says the critical period was around 12-17 hours
   • Evaluation
     • Goslings imprinted on Lorenz cannot be imprinted onto their natural mother as imprinting is evolutionary and cannot be taught. Therefore this experiment resulted in the goslings being deprived of their natural mother
     • Cannot be extrapolated to humans
     • Sluckin says critical period is more of a sensitive period
   • Imprinting is a form of attachment which usually occurs with nidifugous birds where close contact is kept with the first large moving object encountered.

3. Ethical Issues

   • More ethical to conduct experiments on animals than humans
   • Animals have similar genetic make up to humans so some studies can be generalised to humans
   • Animals cannot give informed consent
   • Animals do not have the clear right to withdraw and they cannot exercise that right
   • Studies such Harlow's Rhesus monkeys and the effect of privation can cause distress
   • Animals do not have a genetic make up which matches humans a 100%, therefore data cannot be extrapolated to humans entirely

4. Advantages & Disadvantages

   • Disadvantages: Still unethical to some extent as it can cause distress to the animals and not all studies can be extrapolated to humans
   • Advantages: More ethical than conducting studies and experiment on humans