animal studies - harlow and lorenz Flashcards
when and what did harlow observe?
in 1958, harlow observed that newborns kept alone in a bare cage often died but that they usually survived if given something soft like a cloth to cuddle.
how did harlow test the learning theory?
harlow tested the learning theory explanation of attachment by asking this question: “given a choice between a parent who provides food and one who provides comfort, which parent would the baby choose?”. harlow could not use real life human babies so instead used 8 baby monkeys.
what was harlow’s procedure?
- harlow tested the idea that a soft object serves some of the functions of a mother.
- in his experiment, he reared 16 baby monkeys with two wire model ‘mother’s.
- the monkeys were tested in a controlled laboratory setting and divided into 2 groups.
- in one group, the wire mother was made up of an uncomfortable wire material wheras in the other, the wire mother was made of a comfortable soft towel material.
- for 1 group of monkeys, the milk bottle was on the comfortable mother and for the other group of monkeys the milk bottle was on the uncomfortable mother.
what type of experiment was harlow’s experiment?
a lab experiment
what were harlow’s findings?
- the baby monkeys always preferred to spend time with the comforting towel mother, whether or not she provided milk.
- as well as this, the baby monkeys sought comfort from the comforting towel mother when frightened by a loud noise
- the group with the uncomfortable wire mother only went up to the uncomfortable wire mother for food.
what did harlow conclude?
- that ‘contact comfort’ was of more importance to the monkeys than food when it came to attachment behaviour.
what did harlow and colleagues also do?
- harlow and colleagues 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.
what did the researchers find out about maternal deprivation effects on monkeys?
- the researchers found severe consequences.
- the monkeys in the condition with the uncomfortable wire mother were the most dysfunctional. however, even those in the condition with the comfortable towel mothers did not develop normal social behaviour.
- these deprived monkeys were more aggressive and less sociable than other monkeys and were unskilled at mating.
- when they became mothers, some of the deprived monkeys neglected their young babies.
what could harlow conclude from these findings of monkeys in later life?
- 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.
strength of harlow’s research - real-world applications
- its important real-world applications
- it has helped social workers 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.
limitation of harlow’s research - generalisability to humans
- 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 behaviour.
- 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.
what did lorenz conduct his experiment on?
newly hatched ducklings
what was lorenz’s 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 of eggs hatched in an incubator where the first moving object they saw
was lorenz.
what were lorenz’s findings?
lorenz found 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 phenomenon is called imprinting - where bird species that are mobile (move) from birth attach to and follow the first moving object they see.
- lorenz also identified a critical period in which imprinting needs to take place
- depending on the species, this can be as brief as a few hours after birth. if imprinting didn’t occur within this time, lorenz found the baby geese didn’t attach themselves to a mother figure
what did lorenz also find out about sexual imprinting in a different case study?
in a case study, lorenz described a peacock that had been reared (brung up and cared for) in the reptile house of a zoo where the first moving objects the peacock saw after hatching were giant tortoises.
