Animal studies of attachment

Question 1

Lorenz

Answer 1

Aim: To investigate the effect of imprinting in newly hatched geese.

Procedure:
* Lorenz divided 12 goose eggs into two groups.
* Group 1 was left with their mother and when they hatched, the first moving object they saw was their mother. Group 2 was incubated and when they hatched, the first moving object they saw was Lorenz.
* After some time, Lorenz placed both groups of goslings together to see whether the goslings would follow him or their mother.

Findings:
* Group 1 immediately followed the mother around and Group 2 immediately followed Lorenz around.
* When Lorenz placed all the goslings together, they quickly divided themselves up - one group following their natural mother and the other group following Lorenz. The goslings had formed a strong bond with Lorenz in just the few hours after they had hatched. This is known as imprinting.
* Lorenz found that if imprinting did not occur within a few hours after hatching, the chicks did not attach to the mother figure.

Conclusions:
Lorenz concluded that the process of imprinting is limited to a critical period. If the young animal is not exposed to a moving object during this time frame they will not imprint.
He also suggested that the process is irreversible, long-lasting and has an effect on later mate preferences.
Lorenz believed that imprinting is an adaptive behaviour because the young are protected by being close to the mother, promoting the offspring’s survival and future reproduction.

Question 2

Evaluation Lorenz supporting evidence

Answer 2

• There is supporting evidence for Lorenz’s ideas from other animal studies. For example, other research found that leghorn chicks fed using yellow rubber gloves
  during their first few weeks, imprinted on the gloves. Adult male chicks
  later tried to mate with the gloves. This is a strength as it means that we
  can be more confident that Lorenz’s conclusions are correct; animals will imprint on any moving object during the critical period. This means that the research findings are reliable (consistent)

Question 3

Evaluation Lorenz criticism

Answer 3

However, there is also evidence that challenges the ideas of Lorenz. For example, it was also found that the imprinting that had occurred could be reversed. After spending time with other leghorns, they were able to engage in normal sexual behaviour with other chickens. This shows that Lorenz’s suggestion that the process is irreversible is not entirely accurate.

• Another criticism is that geese and humans are very different and many researchers claim it is inappropriate to generalise (extrapolate) from geese to humans. Human babies are born quite helpless and without the motor skills to move around by themselves, can’t demonstrate imprinting by following their mother around like goslings do. It is widely accepted that geese imprint, whereas humans attach. This means that the conclusions drawn by Lorenz about imprinting, tell us very little about the attachment process in human infants.

Question 4

Harlow

Answer 4

Aim: To investigate whether or not attachment is based on food and being fed.

Procedure:
* 8 newborn rhesus monkeys were taken away from their natural mothers and studied by Harlow for 165 days.
* The monkeys were kept in isolation and given the choice of two surrogate mothers: a wire ‘mother’ with a milk bottle or a wire ‘mother’ covered in a soft cloth.
* Harlow recorded the amount of time the infant monkeys spent with the two different ‘mothers’ and their responses when frightened.

Findings:
* The monkeys spent most of their time with the cloth covered ‘mother’.
* When feeding from the wire ‘mother’ they only spent a minimal amount of time getting milk and then returned to the soft one.
* When they were frightened, they clung to the cloth ‘mother’ and used it as a secure base when playing with new objects.
* There were long-lasting effects of the monkey’s early attachment experiences. Harlow observed that they were unable to socialise with other monkeys (freezing or running away from them) and did not go on to show normal mating behaviour.

Conclusions: Harlow concluded that infants do not develop an attachment to the person who feeds them but the person who offers comfort through contact.

Question 5

Evaluation, Harlow criticisms

Answer 5

Some researchers have suggested that there are methodological issues with Harlow’s research. One significant problem is the potential presence of a confounding variable in the research. The heads of the surrogate mothers were different in that the cloth ‘mother’ had a head with a monkey-like face whereas the wire ‘mother’ didn’t. This is a weakness because it is possible that the infant monkeys spent more time with this ‘mother’ because they found the face more attractive, not because it offered contact comfort.

• Another criticism is that many researchers claim it is inappropriate to generalise from rhesus monkeys to human infants. Although there are similarities between humans and monkeys, humans are very different in that they make conscious decisions. This is a weakness because we cannot confidently say that human infants form attachments in the same way or for the same reasons.
• A final weakness is that the study can be criticised for being unethical. The study caused long-term social and emotional damage to the monkeys, many of which found it difficult to form relationships with their peers. This is a weakness because psychologists have a responsibility to conduct ethical research and it raises questions as to whether research like this should ever be replicated.

Question 6

Evaluation, Harlow practical application

Answer 6

A strength is that this research has a number of practical applications. It suggests that human infants may also need more than just food to be psychologically healthy. This has resulted in policy changes within institutions such as hospitals and children’s homes, leading to more effective care for young children.