Animal Studies of Attachment
Psychology: AQA A Level, topic 3.1.2
Harlow's Animal Studies
Harlow performed a study with monkeys investigating mother-infant attachment. He concluded that there is more to the bond than just nourishment.
Monkey experiment
- In the 1950s, Harlow conducted a series of experiments on monkeys.
- He separated newborn monkeys from their mothers.
- Each monkey was presented with two surrogate mothers.
- One surrogate monkey was made out of wire mesh, and she could dispense milk.
- The other monkey was softer and made from cloth: this monkey did not dispense milk.
Experimental findings
- Research shows that the monkeys preferred the soft, cuddly cloth monkey, even though she did not provide any nourishment.
- The baby monkeys spent their time clinging to the cloth monkey and only went to the wire monkey when they needed to be fed.
- Harlow concluded that there was more to the mother-child bond than nourishment.
Wider implication
- Before this study, the medical and scientific communities generally thought that babies became attached to the people who provided their nourishment.
- Feelings of comfort and security are critical to maternal-infant bonding, which leads to healthy psychosocial development.
Lorenz (1935)
Konrad Lorenz studied the effect of imprinting in geese. Imprinting is important for survival and must happen within a critical period of 13-16 hours.
Imprinting
- Imprinting is when an animal ‘attaches’ to a moving thing, usually immediately after they hatch.
- The ‘moving thing’ is supposed to be their mother (filial imprinting), but Lorenz was imprinted on.
Imprinting in birds
- Imprinting is most common in birds that leave the nest shortly after hatching, including chickens and geese.
- As it happens directly after hatching, it is believed to be an innate instinct that is genetically passed on rather than a learned behaviour.
Lorenz's study of geese
- He hatched a group of greylag geese.
- Half of the geese he incubated and the other half he left with their mother.
- Once the chicks had hatched, the geese that he had incubated followed him around similarly to how the geese followed their natural mother around.
- In other words, the incubated geese had imprinted on Lorenz.
Test - upside-down box
- To test the strength of the imprinting, Lorenz placed all the geese (incubated and hatched by mother) together in an upside-down box.
- When he removed the box and walked away, only his imprinted geese followed him.
- The ones hatched by the mother followed the mother.
Conclusions
- There is a critical period in which imprinting must take place:
- Generally, between 13-16 hours after hatching.
- If the hatchlings did not imprint during this critical period, imprinting did not happen.
- Once the birds have imprinted, they cannot imprint on anything. The imprinting is not reversible.
Humans and imprinting
- Imprinting, in this form, does not happen in humans.
- Attachment happens over a much longer time period and infants can form multiple attachments (though there is a primary attachment, generally to one’s mother).
- The attachment does not happen automatically.
- This being said, Lorenz’s work has formed a basis of the theory of attachment in humans, particularly Bowlby’s internal model of attachment theory.
Ethical issues
- A critique of Lorenz’s work is the ethical issues surrounding the use of animals in studies.
- Some could say that by separating the geese from their mothers, it could have caused distress.
- But the geese were well cared for during the course of his study.
Test yourself on Animal Studies of Attachment
Harlow's Animal Study on Attachment
In Harlow's study into attachment, with which surrogate monkey did the infant monkeys form the strongest bond?
What was the assumption of the medical and scientific communities regarding attachment before Harlow's study?
What type of geese did Lorenz experiment with?
What is a criticism of Lorenz's study?