Animal Studies

Define Imprinting

A phenomenon to describe a form of attachment where offspring follow first large moving object they see

• this is a one way attachment

What was the aim of Lorenz’s experiment

To investigate imprinting in baby geese

Outline Lorenz’s 1953 study

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

  • Control group - natural mother

  • Experimental group - went to Lorenz

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

• Once all eggs from both groups were hatched Lorenz mixed up all the goslings to observe their behaviour, he marked them according to what group they belonged to

When was Lorenz’s study on goslings

1953

Outline Lorenz’s findings from his 1953 study

The non-incubator goslings started to follow their natural mother and the incubator goslings ignored their natural mother and followed Lorenz

What conclusions can be drawn from Lorenz’s 1953 study

• There is an innate element to attachment

• Goslings are pre-programmed to imprint onto the first moving object they see, highlighting the rapid formation of attachment in animals

• The process is long lasting, irreversible and has an effect on later mating preferences (sexual imprinting)

• There is a critical period for imprinting

Define Critical Period

• when does this occur in geese

• when does this occur in monkeys

A time when imprinting needs to occur - Lorenz found that if imprinting didn’t occur, chicks didn’t attach to a mother figure

• Geese - A few hours after birth

• Monkeys - 90 days

Outline the strengths of Lorenz’s study

Research support

• A study by Regolin and Vallortigara (1995) supports Lorenz’s idea of imprinting

• Chicks were exposed to simple shape combinations that moved, e.g a triangle with a rectangle in front

• A range of shape combinations were then moved infant of them and they followed the original more closely

• This supports the vie that animals are born with an innate mechanism to imprint on a moving object present in the critical window of development

Baby duck syndrome

• Despite human attachment being different from birds, there have been attempts to show that a kind of ‘imprinting’ influences human behaviour

• Seebach (2005) suggested that computer users exhibit baby duck syndrome

  • an attachment formed to their first computer system, leading them ti reject others

• This suggests that it is possible to generalise the concept of ‘imprinting’ to humans, but the formation of human attachment is still more complex

Outline the limitations of Lorenz’s 1953 study

Lacks generalisability

• The mammalian attachment system is quite different and more complex to birds

• E.g attachment in mammals is a two way process

• This means it’s not appropriate to generalise Lorenz’s idea of imprinting to humans

Outline the aim of Harlow’s study

To investigate the nature of attachment in Baby Rheus monkeys

Outline the procedure of Harlow’s 1958 study

2 ‘surrogates’

• One 'mother' was made of wood and wire and dispensed milk (in a bottle)

• One mother was made of foam rubber and soft cloth and did not dispense milk

Condition 1 - CCM dispensed milk and WM did not

Condition 2 - CCM did not dispense milk but WM did

• 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

What were the findings of Harlow’s 1958 study

• All of the monkeys spent the most tie with the cloth-covered mother wether she had milk or not

• When frightened they all clung to the CCM

What conclusions can be drawn from Harlow’s 1958 study

• Attachment isn’t simply innate, CII in development is not due to providing food, but rather care

• Contact comfort was more important than food

Outline Harlow’s long term study into maternal deprivation (the monkeys as adults)

• Researched this to see if early maternal deprivation had any real effect - researchers found severe consequences

• Monkeys reared with WM were the most dysfunctional, those with CCM did not develop normal social behaviour

• More aggressive, less sociable and bred less compared to typical monkeys

• Ones that became mothers would often abandon and show aggression towards their young - killing them in some cases

What did Harlow suggest was the cause of the monkey’s long-term behaviour

• Harlow suggested a critical period for dysfunctional behaviour (90 days)

• After this time, the damage was done and attachment became impossible

How does Harlow’s research contradict 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')

Outline the strengths of Harlow’s 1958 study

Real world application

• Psychologists and social workers understand that a lack of parental bonding and nurture can have a detrimental effect 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

Outline the limitations of Harlow’s 1958 study

Lack of generalisability

• 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

Ethical issues

• Research caused long term and severe damage to the monkeys

• However his study does have important theoretical and practical applications

Define sexual imprinting

Example

• Lorenz observed that when a bird imprinted on a human it would often show courtship behaviour towards them