Animal studies of attachment

Animal studies

Studies carried out on non-human animal species rather than on humans.

Either for ethical reasons (some research can’t be done with human participants) or practical reasons (animals breed faster and researchers are interested in seeing results across more than one generation)

Imprinting

Where bird species that are mobile from birth attach to and follow the first moving object they see.

Lorenz 1952 study

Observed imprinting when he was a child and was given a newly hatched duckling that followed him around.

Randomly divided a large clutch of goose eggs. Half hatched with the mother goose in their natural environment (control group). The other half hatched in an incubator where the first moving object they saw was Lorenz

The incubator group followed Lorenz everywhere whereas the control group followed the mother. When the 2 groups were mixed the control group still followed the mother and the experimental group followed Lorenz.

Identified a critical period in imprinting needs to take place. In chicks this period can be as short as a few hours after hatching. If imprinting did not happen within that time Lorenz found that chicks didn’t attach themselves to a mother figure

Sexual imprinting Lorenz

Investigated the relationship between imprinting and adult mate preferences. He observed that birds that imprinted on humans would 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 objects the peacock saw after hatching were giant tortoises.

As an adult this bird would only direct courtship behaviour towards the tortoices.

He concluded that this meant the peacock had undergone sexual imprinting

Harlow 1958 study

Tested the idea that a soft object serves some of the functions of a mother. 

Reared 16 baby monkeys with 2 wire model mothers.

In 1 condition milk was dispensed by a plain-wire mother and in the other milk was dispensed by the cloth-covered mother.

Baby monkeys cuddled the cloth-covered mother more than the plain-wire one and sought comfort from the cloth one when frightened regardless of which mother dispensed milk.

Suggested that contact comfort was more important to the monkeys than food when it came to attachment behaviour.

Maternal deprivation

Harlow and colleagues also followed monkeys who had been deprived of a real mother into adulthood to see if early materinal deprivation had a permanent effect.

Found severe consequences.

Monkeys reared with plain-wire mothers were the most dysfunctional.

The ones with a cloth-covered mother did not develop typical social behaviour. More aggressive and less sociable than other monkeys. Bred less often than normal.

If they were mothers, they neglected their young and some attacked their young.

Critical period for typical development

Harlow concluded that there was a critical period for attachment formation - a mother had to be introduced to a young monkey within 90 days of their birth for an attachment to form. 

After this time attachment was impossible and early deprivation damage became irreversible

Lorenz

S Guiton

Chicks who relied on yellow gloves to feed them were imprinted to them and tried to mate with them

Supports Lorenz’s findings.

Suggests imprinting is not limited to certain objects

Lorenz

W No Critical Period

A study found that ducklings in isolation for 5 days could still imprint.

Suggests that failing to imprint in the critical period can be reversible.

Suggests there is a sensitive period rather than critical

W Generalisability

The research tries to explain attachments in humans by looking at the effects an infant has if there is no attachment formed in the critical period.

Human behaviour is more conscious than in animals. We may develop attachments differently.

Not always possible to generalise animal research to humans

Harlow

S Applications

Helped clinical psychologists and social workers understand that adult difficulties maybe rooted in poor early bonding experiences.

Harlow’s research has been applied to improving the welfare of infant primates in zoos

The value of Harlow’s research theoretical and practical

Harlow

W Extraneous variables

The cloth mother’s head was more attractive than the wire mother’s. Limits the ability to give cause and effect relationship as the appearance may cause the monkey to spend more time with the cloth mother.

Lowers internal validity

Harlow

W Ethical issues

Research led to distress and long-lasting emotional harm.

Some monkeys who were only allowed access to a wire mother for 6 months couldn’t recover from the effects.

Animals can’t give consent.