Don’t need - Animal Studies Of Attachment Flashcards
When was Lorenz study conducted?
1935
What is imprinting?
An innate readiness to develop a strong bond with the mother which takes place during a specific time in development, probably the first few hours after birth/hatching.
If it doesn’t happen at this time it probably will not happen.
What was Lorenz’s procedure for the study?
He took a clutch of gosling eggs and divided them into two groups.
One group was left with their natural mother while the other eggs were placed in an incubator.
When the incubator eggs hatch the first living (moving) thing they saw was Lorenz and they soon started to follow him around.
To test the effect of imprinting Lorenz marked the two groups to distinguish them and placed them together, under a box. Both Lorenz and their natural mother were present.
What did Lorenz find?
The goslings quickly divided up, one following their natural mother and the other group following Lorenz.
Lorenz’s brood showed no recognition of their natural mother.
He noted that this process of imprinting is restricted to a very definite period in the young animals life, called the critical period.
If a young animal isn’t exposed to a moving object during this critical period the animal wont imprint.
This suggests animals can imprint on a persistently present moving object seen within its first two days.
Lorenz did observe that imprinting to human does not occur in some animals, for example curlews.
What were the long-lasting effects of Lorenz’s study?
Lorenz 1952 - noted several features of imprinting, for example that the process is irreversible and long lasting.
He described how one of the geese slept on his bed every night.
He also noted that this early imprinting has an effect on alter mate preferences, called sexual imprinting - animals (especially birds) will choose to mate with the same kind of object upon which they were imprinted.
What are the evaluative points for Lorenz’s study?
Research support for imprinting
Criticisms of imprinting
What is meant by research support for imprinting? (Lorenz)
Guiton (1966) demonstrated that leghorn chickens, exposed to yellow rubber gloves for feeding them during their first few weeks, beamed imprinted on the gloves.
This supports the view that young animals are not born with a predisposition to imprint on a specific type of object but probably on any moving thing that is present during the critical window of development.
Guiton also found that the male chickens later tired to mate with the gloves, showing that early imprinting is linked to later reproductive behaviour.
What is meant by criticisms of imprinting? (Lorenz)
The original concept of imprinting, that an encounter with an appropriate object leads to the image of that object being somehow stamped irreversibly on the nervous system.
Now it is understood that imprinting is a more ‘plastic and forgiving mechanism’ (Hoffman, 1966). For example, Guiton found that he could reverse the imprinting in chickens who had initially tried to mate with the rubber gloves. He found that later, after spending time with their own species, they were able to engage in normal sexual behaviour with other chickens.
It is also now thought that imprinting may not, after all be so very different from any other kind of learning.
When was Harlow’s study conducted?
1959
What was Harlow’s study on?
He sought to demonstrate that mother love (attachment) was not based on the feeding bond between mother and infant as predicted by learning theory.
What procedure did Harlow use in his study?
Harlow created two wire mothers each with different heads. One wire mother additionally was wrapped in soft cloth.
8 rhesus monkeys were studied for a period of 165 days. For 4 of the monkeys the milk bottle was on the cloth-covered mother and on the plain wire mother for the other 4 monkeys.
During that time measurements were made of the amount of time each infant spent with the two different mothers.
Observations were also made of the monkey infants responses when frightened by, for example, a mechanical teddy bear.
What did Harlow find from his study?
All 8 monkeys spent most of their time with the clothmother whether or not this mother had the feeding bottle.
These monkeys who fed from the wire mother only spent a short amount of time getting milk and then returned to the cloth mother.
When frightened, all monkeys clung to the cloth mother, and when playing with new objects the monkeys often kept one foot on the cloth mother seemingly for reassurance.
These findings suggest that infants do not develop an attachment to the person who feeds them but to the person offering contact comfort.
What are the long-lasting effects of Harlow’s research?
He continued to study the rhesus monkeys as they grew up and noted many consequences of their attachment experiences:
He reported that the motherless monkeys, even those who had contact comfort, developed abnormally.
They were socially abnormal - they froze or fled when approached by other monkeys.
They were sexually abnormal - they didn’t show normal mating behaviour and didn’t cradle their babies.
What was the critical period Harlow found for the long-lasting effects?
Harlow also found that there was a critical period for these effects. If the motherless monkeys spent time with their monkey peers they seemed to recover but only if this happened before they were 3 months old.
Having more than 6 months with only a wire mother was something they did not appear able to recover from.
What are the evaluative points of Harlow’s studies?
Confounding variable
Generalising animal studies to human behaviour
Ethics of study
