Animal studies on attachment

what’s imprinting?

an innate readiness to develop a strong bond with the mother which takes place during specific time in development, probably the first few hours after birth/hatching if it doesn’t happen at this time it probably wont happen

What did Lorenz demonstrate?

The concept of imprinting

what was Lorenz procedure

• Took a clutch of gossling eggs and divided them into two groups

• One group was left with their natural Mother The other eggs were placed in an incubator

• When the incubator eggs hatched the first thing they saw was Lorenz and they soon started following him around

• when the mother hatched eggs hatched they saw their mother first

• when the flock was mixed together again, geese reliably returned to whoever they imprinted on

What were the findings of Lorenz?

• noted that this process of imprinting is restricted to a very definite period of the young animals life called a critical period

• If a young animal is not exposed to moving object during this early critical period, the animal will not imprint

• imprinting is irreversible and long lasting

what was Lorenz’s conclusion?

suggest animals can imprint on a persistently present moving object seen within a first few days

Why does imprinting occur much earlier in animals than in humans?

Animals are at threat from predators

What is the critical period for animals?

Less than 24 hours

What is the critical period for humans?

7 months

What was the IV of Lorenz?

1. Hatched by goose mum

2. hatched by incubator by Lorenz

what was the DV of Lorenz?

Who geese imprinted on goose mum or lorenz

Imprinting forms adult sexual behaviour evidence

• Lorenzo Greylag geese who imprinted on him went onto when they were adults performing mating displays with humans and ignored other geese

• Loren’s peacock brought up in a reptile house went onto display affections for reptiles

• geese imprinted on a goose Mother went on to when they were adults performing mating displays with other geese

What was Harlow’s definition of imprinting?

• animals have an innate drive to attach to their primary caregiver

• Once imprinted, they recognise and seek proximity with this figure

• This provides protection and allows them to learn important behaviours

• Imprinting must occur within a certain timeframe critical period or it will never happen

• Imprinting is irreversible and lasting

what did Harlow propose?

Proposed that attachment was driven by contact comfort (emotional care) not food (classical conditioning) as was assumed by behaviourist at the time

What was Harlow’s procedure?

• created two wire mothers each with a different head

• One wired mother additionally was wrapped in soft cloth

• monkeys were studied for a period of 165 days

• For four of the monkeys, the milk bottle was on the cloth covered Mother and on the plain wire Mother for the other 4 monkeys

• during that time measurements were made of the amount of time each infant spent with the two different mothers

• Observations were also made of the monkey infants responses when frightened by for example a mechanical teddy bear

What and how many monkeys did Harlow study?

8 infant rhesus monkeys

what was the confounding variable for Harlows monkeys?

faces of represented Mother

what were Harlows findings?

• all eight monkeys spent most of their time with the cloth covered Mother whether or not this Mother had the feeding bottle

• those monkeys who fed from the wire Mother only spent a short amount of time getting milk and then returned to the cloth covered Mother

• when frightened all monkeys clung to the cloth covered mother

• when playing with new objects, the monkeys often kept 1 foot on the cloth covered Mother seemingly for reassurance

what was the conclusion from Harlow?

The finding suggest the infants do not develop an attachment to the person who feeds them but the person offering contact comfort

What were the long lasting effects of Harlow study?

• reported that the motherless monkeys even those who did have contact comfort developed abnormally they were socially abnormal. They froze or flood when approached by other monkeys and they were sexually abnormal. They did not show normal behaviour and did not cradle their babies.

• also found that there was a critical period for these effects

• If the motherless monkey spent time with their monkey peers, they seemed to recover but only if this happened before they were three months old having more than six months with only wired Mother was something they did not appear able to recover from

what is the research support for imprinting

• A number of other studies have demonstrated imprinting in animals

• Guiton Demonstrated that leghorn chicks Exposed to yellow rubber gloves while being fed during the first few weeks becoming imprinted on the gloves

• This supports the view that young animals are not born with bred disposition to imprint on a specific type of object, but probably on any moving thing that is present in the critical window of development

• Also found that the male chicks tried to mate with the gloves showing that early imprinting has link to later reproductive behaviour

What are the criticisms of imprinting?

• there are some disputes over the characteristics of imprinting

• For many years, the accepted view of imprinting was that it was an irreversible process

• Now it is understood that imprinting is a more plastic and forgiving mechanism

• Guiton found that he could reverse the imprinting in chickens that had initially tried to make with the rubber gloves and later after spending time with their own species they were able to engage in normal sexual behaviour with other chickens

Evaluation of Harlows research

• confounding variable - The two heads were also different which acted as a confounding variable because it varied systematically with the independent variable. It is possible that the Monkeys preferred one Mother to the other because the cloth covered Mother had a more attractive head.

• Generalising animal studies to human behaviour - The ultimate aim of animal studies is to be able to generalise the conclusions to human, However humans differ in important ways perhaps most important because much more of their behaviour is governed by conscious decisions we are more complex lack the emotional responses humans have

• Ethics of hollow study - Hallows could not be done with humans, but there’s also a question of whether it should be done on monkeys, Created lasting emotional harm as the monkeys they found it difficult to form relations with their peers unethical to cause harm to animals for purposes of learning about human attachment

What was the critical period for monkeys?

90 days

what are the strengths of animal studies on attachment?

• there are implications for theories of attachment (bowlby’s monotropy theory, adaptive links to imprinting, critical period lorenz and harlow)

• challenges LT (higher importance of contact comfort)

• provides the foundation for theories to help explain the formation of attachment

• practical application (long term consequences on children importance for attachment at early stages of development helps social workers identify)