Animal Studies Flashcards
Summarise Lorenz study
Lorenz used a LABORATORY experiment and randomly divided a clutch of gosling eggs into two groups (independent groups design).
• Control group - half the eggs were left with the mother goose in their natural environment
• Experimental group - half of the eggs were placed in an incubator. When they hatched the first moving object they saw was Lorenz.
Imprinting Definition: A rapid learning process by which a newborn animal establishes a behaviour pattern of recognition and attraction towards other animals of its own kind, as well as to specific individuals of its species, such as its parents, or to a substitute for these.
To test the effects of imprinting, Lorenz marked the two groups to distinguish them and placed them together. Both Lorenz and their natural mother were present.
Long term effects - In order to study any long term effects Lorenz also followed the geese into adulthood to see if early maternal deprivation had a permanent effect.
What were the findings of Lorenz study
Imprinting - The experimental group who had seen Lorenz first followed him closely, as if he were their mother and appeared to have formed a rapid attachment with him. In contrast, the control group followed their biological mother.
After Lorenz put all the goslings together, he found that the two groups separated to go to their respective ‘mothers’ - half to the goose, and half to Lorenz.
Long term effects – Lorenz noted that the process of imprinting is IRREVERSIBLE and long lasting. He also found that early imprinting had an effect on later mate preferences, called sexual imprinting.
Findings - Critical period - Lorenz also identified a critical period in which imprinting needed to have taken place. If imprinting does not occur within this time, Lorenz found that chicks did not attach themselves to a mother figure.
Conclusion - Lorenz’s research highlighted the importance of imprinting in animals and the evolutionary advantage of forming an attachment. This is because the young animal that follows its mother is more likely to be safe from predators, to be fed and to learn how to find food, i.e. to increase their chances of survival and natural selection.
What is research support for imprinting and critical period?
Guiton (1966) exposed leghorn chicks to yellow rubber gloves whilst feeding them, during their first few weeks after birth. They found that they became imprinted on the glove. This supports the view that young animals are not born with a predisposition to imprint on a specific object but on any moving object that is present during the critical window of development. This suggests there is a ‘window of opportunity’ (critical period) in which attachments must be formed otherwise this may lead to negative long-term consequences, this was also found to be true of humans in Bowlby’s Theory of Maternal Deprivation.
What is contradictory evidence for Lorenz study?
imprinting is IRREVERSIBLE. In Guiton’s research, when the chickens matured and spent some time with their own species, they engaged in normal mating behaviour. This therefore illustrates that imprinting CAN be reversed beyond the critical window of development, like many other forms of learning. In humans it has also been found that the critical period may be more of a ‘sensitive period’ as studies, such as the Romanian orphan studies, have demonstrated that children have recovered from the effects of early deprivation. This suggests that imprinting is not as permanent as Lorenz once thought.
Summarise Harlows research
Procedure - Harlow used a LABORATORY experiment in order to rear baby monkeys. He split the monkeys into two groups (independent groups design)
• Condition one – the cloth mother provided milk and the wire monkey didn’t (4 monkeys)
• Condition two – the wire monkey provided milk and the cloth monkey didn’t (4 monkeys)
The monkeys were studied for a period of 165 days. During that time, measurements were made of the amount of time each spent with the two different ‘mothers’. Observations were also made of the monkey infants responses when frightened, for example, by a mechanical teddy.
Long term effects - Harlow also followed the monkeys into adulthood and recorded the long-term effects on sociability and relationships with offspring.
What were the findings of harlows study?
Findings – sociability and relationship to offspring
It was found that the baby monkeys spent most of the time with the cloth-covered monkey whether or not this mother had the feeding bottle. Those monkeys who fed from the wire monkey only spent a short amount of time getting milk and then returning to the cloth-covered mother. When frightened, all monkeys clung to the cloth-covered monkey and when playing with new objects, the monkeys often kept one foot on the cloth-covered mother seemingly for reassurance.
Long term effects – Harlow found that these motherless monkeys developed abnormally into adulthood. They were more aggressive and less sociable than other monkeys (they froze or fled when approached by other monkeys) and they bred less often than is typical for monkeys. As mothers some of the deprived monkeys neglected their young and others attacked and sometimes killed their children.
Findings - Critical period - Like Lorenz, Harlow also found a critical period for these effects. A mother figure had to be introduced to an infant monkey within 90 days for an attachment to form. After this time, attachment was impossible and the damage done by early deprivation became irreversible.
What is the practical application for Harlow research ?
– A strength of Harlow’s research is that it went against the dominant belief that attachment was related to physical care (i.e. food) and instead showed the importance of emotional care. This was further supported in human studies, Schaffer and Emerson found mothers responsiveness mattered most in the formation of attachment between caregiver and infant. This led to important practical applications with both humans and animals. For example, it has helped social workers understand risk factors in child neglect and abuse and so intervene to prevent it (Howe, 1998). These findings were also important in the care of captive monkeys as we now understand the importance of adequate attachment figures for babies in zoos and also in breeding programmes in the wild. This therefore illustrates how Harlow’s research has been used in a number of contexts and has practical value.
What is the problem with extrapolating to attachment in human infants.?
Although a strength of animals studies is that that they have influenced research into human attachment such as Bowlby’s idea of a critical period in human babies and they have influenced our understanding of human development, there is a problem of extrapolating (generalising) from findings on animals to humans. Human attachment behaviour is very different to other animals especially as much more of our behaviour is governed by conscious decisions. Mammalian mothers for example, show more emotional attachment to their young than birds do. This means that it may not be appropriate to try and generalise the work from animal studies in order to explain human attachment.
What are the ethical issues with both studies
both studies created stress to the young animals after being separated from their mothers. They also caused long term emotional harm as the animals found it difficult to form relationships as adults including the formation of appropriate mating strategies. However, the experiments can be justified in terms of the significant effect they had on our understanding of the process of attachment in humans at that time. It therefore could be argued that the benefits outweigh the costs to the animals and is something to consider when monitoring what counts as good science.
