4. animal studies Flashcards
LORENZ’S RESEARCH - IMPRINTING
PROCEDURE:
Lorenz set up a classic experiment in which he randomly divided a large clutch of goose eggs.
Half the eggs were hatched with the mother goose in their natural environment.
The other half hatched in an incubator where the first moving object they saw was Lorenz.
AO3: strength of ANIMAL STUDIES - LORENZ
research support - Regolin (chicks)
One strength of Lorenz’s research is the existence of support for the concept of imprinting.
A study by Regolin supports Lorenz’s idea of imprinting. Chicks were exposed to simple shape combinations that moved, such as a triangle with a rectangle in front. A range of shape combinations were then moved in front of them, and they followed the original most closely.
This supports the view that young animals are born with an innate mechanism to imprint on a moving object present in the critical window of development, as predicted by Lorenz.
LORENZ’S RESEARCH - IMPRINTING FINDINGS:
The incubator group followed Lorenz everywhere whereas the control group, hatched in the presence of their mother, followed her. When the two groups were mixed up the control group continued to follow the mother and the experimental group followed Lorenz.
This is called imprinting - whereby bird species that are mobile from birth attach to and follow the first moving object they see.
SEXUAL IMPRINTING
Lorenz also investigated the relationship between imprinting and adult mate preferences. He observed that birds that imprinted on a human would often later display courtship behaviour towards humans.
In a case study Lorenz described a peacock
that had been reared in the reptile house of a zoo where the first moving objects the peacock saw after hatching were giant tortoises. As an adult this bird would only direct courtship behaviour towards giant tortoises. Lorenz concluded that this meant the peacock had undergone sexual imprinting.
Lorenz identified a critical period of
4-25 hours in which imprinting needs to take place. If imprinting does not occur within that time Lorenz found that chicks did not attach themselves to a mother figure.
AO3: limtation of ANIMAL STUDIES - LORENZ
low generalisability
One limitation of Lorenz’s studies is the ability to generalise findings and conclusions from birds to humans.
The mammalian attachment system is quite different and more complex than that in birds. For example, in mammals’ attachment is a two-way process, so it is not just the young who become attached to their mothers but also the mammalian mothers show an emotional attachment to their young.
This means that it is probably not appropriate to generalise Lorenz’s ideas to humans.
HARLOW’S RESEARCH
Harlow worked with rhesus monkeys, which are much more similar to humans than Lorenz’s birds.
PROCEDURE:
Harlow tested the idea that a soft object serves some of the functions of a mother. In one experiment he reared 16 baby monkeys with two wire model ‘mothers’.
In one condition milk was dispensed by the plain-wire mother whereas in a second condition the milk was dispensed by the cloth- covered mother.
HARLOW’S RESEARCH
FINDINGS
The baby monkeys cuddled the cloth-covered mother in preference to the plain-wire mother and sought comfort from the cloth one when frightened regardless of which mother dispensed milk.
This showed that ‘contact comfort’ was of more importance to the monkeys than food when it came to attachment behaviour.
MATERNALLY DEPRIVED MONKEYS AS ADULTS
Harlow also followed the monkeys who had been deprived of a ‘real’ mother into adulthood to see if this early maternal deprivation had a permanent effect - severe consequences.
The monkeys reared with plain-wire mothers only were the most dysfunctional.
However, even those reared with a cloth-covered mother did not develop normal social behaviour.
These deprived monkeys were
more aggressive and less sociable than other monkeys and they bred less often than is typical for monkeys, being unskilled at mating.
When they became mothers, some of the deprived monkeys neglected their young and others attacked their children, even killing them in some cases.
Harlow concluded that there was a critical period for attachment formation - a mother figure had to be introduced to a young monkey within
90 days for an attachment to form. After this time attachment was impossible and the damage done by early deprivation became irreversible.
AO3: strength of ANIMAL STUDIES - HARLOW
real world applicaitons
One strength of Harlow’s research is its important real-world applications.
For example, it has helped social workers and clinical psychologists understand that a lack of bonding experience may be a risk factor in child development allowing them to intervene to prevent poor outcomes. We also now understand the importance of attachment figures for baby monkeys in zoos and breeding programmes in the wild.
This means that the value of Harlow’s research is not just theoretical but also practical.
AO3: limitation of ANIMAL STUDIES - HARLOW
low generalisability
One limitation of Harlow’s research is the ability to generalise findings and conclusions from monkeys to humans.
Rhesus monkeys are much more similar to humans than Lorenz’s birds, and all mammals share some common attachment behaviours. However, the human brain and human behaviour is still more complex than that of monkeys.
This means that it may not be appropriate to generalise Harlow’s findings to humans.
