Animal studies of attachment

Imprinting definition

An innate (natural) readiness for animals to develop a strong bond with a mother

Takes place soon after hatching/birth

Who was Konrad Lorenz?

An ethnologist, studying animal behaviour under relatively natural conditions.

Although his research did involve some manipulation.

Aim of Lorenz 1935 study

To test the effect of imprinting on goslind

Procedure of the study

Lorenz divided a clutch of gosling eggs into two, placed one half into an incubator and left the other with the natural mother.

The incubator eggs hatched and the first living thing they saw was Lorenz, so they started following him around.

Lorenz marked the two groups to distinguish them and placed them together. Both Lorenz and the natural mother were present.

Findings of the study

Lorenz’s goslings followed him around, showed no recognition of their natural mother

Conclusions of the study

The process of imprinting is restricted to the critical period of the animal’s life (can happen within animals first two days).

If a young animal isn’t exposed to a moving object during this critical period, the animal won’t imprint.

Imprinting is a process similar to attachment that binds a young animal to a caregiver in a special relationship

Lorenz also later observed that imprinting to humans simply doesn’t occur in some animals (eg curlews)

What were the long lasting effects of imprinting that Lorenz found?

The process of imprinting is irreversible and long lasting.

The early imprinting had an effect on later mate preferences (sexual imprinting) -

animals (especially birds) will choose to mate with the same kind of object to which they were imprinted

Positive eval

Research support for imprinting - study by Guiton (1966) imprinted chicks on yellow rubber gloves.

This supports the view of the critical period and type of object being crucial for imprinting.

Guiton also found that the male chickens later tried to mate with the gloves - proves that early imprinting is linked to later reproductive behaviour.

Negative eval

Disproving Lorenz - Guiton (1966) found that he could reverse the imprinting on the chicken that tried to mate with the rubber gloves. He found that they were able to engage in normal sexual behaviour after spending time with their own species.

Also it can be argued that Lorenz’s studies were unethical for taking the goslings away from their natural mother.

What was the aim of Harlow’s 1959 study?

To demonstrate that mother love (attachment) was NOT based on the feeding bond between mother and infant, as stated by learning theory.

Procedure of Harlow’s study

Harlow created eight sets of two ‘wire mothers’ (fake mothers made of wire) each with a different ‘head’.

One wire mother was additionally wrapped in soft cloth.

Eight infant monkeys were studied for a period of 165 days with these two wire mothers.

For four of the monkeys, the milk bottle was on the cloth-covered mother, and on the plain wire mother for the other four monkeys.

Procedure - What was Harlow measuring and observing?

In the 165 days, measurements were made of the amount of time each infant spent with the two different mothers.

Observations were also made of the monkey infant’s responses when frightened by certain things (eg mechanical teddy bear).

Additional procedures of the study

‘Open field’ test

Findings of the study

All monkeys spent most of their time with the cloth-covered mother, whether she had the milk or not

When frightened, all monkeys clung to the cloth-covered mother

When playing with new objects, the infants often kept one foot on the cloth-covered mother for reassurance

What was the conclusion of the study

Infants develop an attachment to the person offering contact comfort, not to the person who feeds them

Long-lasting effects of the study

Harlow continued to study these monkeys throughout their lives.

All the monkeys developed abnormally. They were socially abnormal - didn’t know what species they were or how to interact - and sexually abnormal - abnormal mating behaviour and didn’t cradle their own babies.

Harlow found that there was a critical period for these effects - 3 months with a wire mother was recoverable but 6 months was not

Negative eval

The heads of the two wire mothers were different - extraneous variable. It is possible that the cloth-covered mother simply had a more attractive head. So the conclusions of the study lack internal validity.

Humans and animals are very different, so this is a generalisation to compare with humans. Humans make more conscious decisions and have a larger IQ.

HOWEVER… Harlow’s research is supported by Schaffer and Emerson’s findings, that infants aren’t most attached to the person who feeds them.

Unethical - the monkeys were confused and didn’t know how to form relationships with peers.

Positive eval

Harlow’s conclusion that infants don’t gain attachment from being given food is supported by Schaffer and Emerson’s findings

Had a significant effect on understanding of attachment, led to better care for infants. So can be argued that the benefits outweigh the costs to animals involved in the study.