Animal studies of attachment

Harlow’s monkeys

A: study the mechanisms by which newborn monkeys bond with their mothers

P: 8 monkeys separated from their mothers immediately after birth and placed in cages with access to two surrogate mothers (one made of wire and one covered in cloth). 4 of the monkeys could get milk from the wife mother, 4 from the cloth mother. studied for 165 days

F: both groups spent more time with the cloth mother. if a threat was presented, the infant took refuge with the cloth mother (decreasing fear). behavioural differences included being more timid, easily bullied, difficulty mating

C: supports the evolutionary theory of attachment = the sensitive response and security of the caregiver is more important than the provision of food. for a monkey to develop normally, they must have some interaction with an object they can cling to during the critical period. infant monkeys suffered more from social deprivation rather than maternal deprivation

Lorenz (1935)

A: investigate mechanisms of imprinting (infants from an attachment to the first large moving object they meet)

P: split large clutch of goose eggs into 2 batches (1 hatched naturally by the mother, 1 hatched in an incubator). he then recorded the behaviour. he placed them all under and upturned box, then removed them and recorded their behaviour

F: immediately after birth the naturally hatched goslings followed their mother, while the incubator hatched ones followed Lorenz. permanent imprinting occurred within the first few hours after birth (the critical period)

one strength of Lorenz’s research is other research support for imprinting

Guilton (1966) found that leghorn chicks, exposed to yellow rubber gloves while being fed during their first few weeks became imprinted on the gloves

supports the view that young animals are not born with a predisposition to imprint on a specific type of object but probably on any moving thing that is present during the critical period

Guiton also found that the male chickens later tried to mate with the gloves = imprinting is linked to later reproductive behavior

clear support for Lorenz’s original conclusions

one limitation of Lorenz’s research is criticisms of imprinting

Hoffman (1996) states imprinting is more a ‘plastic and forgiving mechanism’ rather that an irreversible process

Guiton (1966) found that imprinting could be reversed in the chickens that had initially tried to mate with the rubber gloves = after spending time with their own species they were able to engage in normal sexual behaviour with other chickens

suggests that imprinting is not different from other kinds of learning = can take place rapidly, with little conscious effort, reversible

one limitation of Harlow’s research is methodological issues

the two stimulus objects varied in more ways than just being cloth or not (different heads) = acted as a confounding variable because it varied systematically with the independent variable

possible that the reason the infant monkeys preferred the cloth mother was because it had a more attractive head

lacks internal validity

one limitation of Harlow’s research is generalising animal studies to human behaviour

humans differ (more behaviours governed by conscious decisions)

regardless, many studies have found that the observations made of animal attachment behaviour are mirrored in studies of humans (e.g. Schaffer and Emerson found that infants were not most attached to the person who fed them)

though animal studies can be useful in understanding human behaviour, findings should be confirmed by looking at research with humans