Animal Studies in Attachment: Lorenz & Harlow (AQA AS Psychology)

Lorenz's geese study

• Konrad Lorenz was an ethologist who worked predominantly in natural conditions in the natural world

• One behaviour Lorenz was interested in was the behaviour of imprinting

Imprinting

• Imprinting is much like attachment in human infants as it bonds a baby animal to its caregiver

• Imprinting is where an offspring will follow the first moving object they see once born

• This phenomenon occurs commonly in birds but also in many mammals and some fishes and insects

• Lorenz hypothesised that if baby animals can imprint after such a short space of time then attachment must be innate

Lorenz's goslings

• A key piece of Lorenz's research (1935) involved goslings (baby geese)

• Procedure:

  • Lorenz randomly split a clutch of goose eggs into two groups

    • One group was left in their natural habitat with their biological mother (the control group)

    • One group was placed in an incubator (the experimental group)

  • Upon hatching, the incubator eggs' first living and moving thing they saw was Lorenz

  • Upon hatching, the control group eggs' first living and moving thing they saw was their natural mother

  • Once all eggs from both groups were hatched Lorenz mixed up all the goslings to observe their behaviour

• Findings:

  • The goslings from the control group followed their natural mother

  • The goslings from the experimental group followed Lorenz - they had imprinted on him

  • Lorenz identified a critical period when imprinting occurs

    • If exposure to a moving object does not happen during the critical period then attachment to a 'mother' figure does not occur i.e. the bird will not imprint

    • The critical period is different for different species of bird, although Lorenz observed this to be between 13 and 16 hours shortly after hatching for the goslings

Evaluation

Strengths

• There are many supporting studies on the concept of imprinting

  • Guiton (1966) used yellow rubber gloves to cause imprinting of newly hatched leghorn chicks

  • This suggests that young birds (animals) are not born with a predisposition to imprint onto a specific species, but anything that is consistently moving during the critical period

  • This means there is clear support for Lorenz's research and findings of imprinting during a critical period

• The findings of Lorenz's research have influenced other areas of psychology, such as developmental psychology

  • Lorenz suggested that imprinting was irreversible which suggests that imprinting is controlled by biological factors and happens within a certain time frame

  • This has led to other psychologists (such as Bowlby) developing well-studied theories of attachment which also suggest that attachment takes place during a critical period and is a biological process.

  • This has good practical applications as attachment theory has influenced the way child care is administered

Limitations

• Lorenz's study into gosling imprinting cannot be generalised to humans

  • Attachment in mammals, and specifically humans, is very different to that of bird species

    • Attachment in humans is a two-way process (formed by reciprocity and interactional synchrony): the mother attaches to the baby and the baby attaches to the mother

    • Birds can imprint onto inanimate objects meaning that it is a one-way relationship

• Other research has found that imprinting is changeable and not permanent

  • One study found that chickens that had originally imprinted onto a rubber glove and tried to mate with rubber gloves, were able to have this reversed after spending more time with their own species

  • This suggests that imprinting may be more similar to learning rather than a form of attachment

Harlow's monkey study

• Harry Harlow was an American psychologist

  • He studied attachment and is most well-known for his experiments with rhesus monkeys (1958) which focused on

    • maternal-separation

    • dependency needs

    • social isolation

• Harlow had observed that newborn rhesus monkeys often died if they were kept alone in a cage but survived if they had a soft cloth to cuddle to

• Harlow investigated how attachment to a mother was not based on feeding (i.e basic needs) but instead, attachment is formed through being comforted

• Procedure

  • Two fake (and very rudimentary) wire 'mother monkeys' were created

    • Each had a different head type (see photo below)

    • The bodies were also different - one was covered in a cloth, the other was a bare wire with no padding

  • Eight infant rhesus monkeys were split into two groups of four and studied over 165 days

    • One group had milk dispensed via the cloth 'mother'

    • The other group had milk dispensed via the plain-wire 'mother'

  • Data was collected on the amount of time the monkeys spent on each 'mother'

  • Observations were made in additional experiments on how the monkeys reacted to being scared

• Findings

  • All eight monkeys spent the majority of time with the cloth 'mother'

  • Monkeys whose milk was delivered via the plain wire ' mother' only spent time there feeding, then returned to the cloth 'mother'

  • When scared, all monkeys held onto the cloth mother

  • When playing/investigating new objects monkeys kept one limb on the cloth mother

  • This suggests that contact and comfort are how attachment is formed, rather than through feeding

• Long-term study

  • Harlow observed the monkeys into adulthood to investigate maternal deprivation

  • Both groups of monkeys developed abnormally

  • The monkeys raised with the plain-wire 'mother' were most dysfunctional:

    • More aggressive

    • Less sociable

    • Bred less/unskilled at mating

    • Attacked their offspring (when breeding was successful)

  • Harlow discovered a critical period for dysfunctional behaviour

    • The monkeys who spent time socialising with other monkeys before the age of three months showed that some of the abnormal behaviours could be reversed

    • Monkeys who spent more than six months in isolation with only a wire mother did not recover normal monkey behaviour

Image courtesy of Photo Researchers, Inc./SCIENCE PHOTO LIBRARY

Evaluations

Strengths

• Harlow's research and experiments on monkeys have real-world applications

  • Psychologists and social workers can understand that a lack of parental bonding and nurture can have detrimental effects on a child's development

  • This means that interventions can be put in place to prevent long-term negative consequences

  • Animal care can also be improved in settings such as zoos, wildlife centres and breeding programmes

Limitations

• The findings of Harlow's research cannot be generalised to humans

  • Whilst monkeys are similar to humans (both are primate mammals), there is still a wide variety of differences physically and in our behaviours and emotions

    • Humans are more complex than monkeys

• The experiments carried out by Harlow on monkeys raised many ethical issues

  • Harlow's research caused severe and lasting distress to animals that found it difficult to form relationships with other monkeys and displayed unsettling and abnormal behaviour

  • This means that Harlow's study is not ethically sound

  • It is important to question whether the effects on the monkey outweigh the findings of the study and gains to attachment research

• The findings from Harlow's experiments contradict the learning theory of attachment

  • Harlow found that monkeys spent more time with the cloth mothers, even when they were not being fed from these

  • Whilst the learning theory of attachment suggests that attachment to a caregiver is formed based on an association between caregiver and food

  • Harlow's evidence suggests that baby monkeys do not form attachments based on food, but prefer ‘contact comfort’ from a caregiver figure (the cloth 'mother')