animal studies of attachment

• comparative psychology is the study of animals to find out about humans. the underlying assumption is that to some degree the laws of behaviour are the same for all species and that therefore knowledge gained by studying animals can be generalised to humans
• Lorenzs (1935) aim was to examine the phenomenon of imprinting in non human animals which is where the offspring follows and forms attachment bond to the first large moving object they see
• Lorenz method: lorenz conducted an experiment where he randomly divided greylag goose eggs into two batches. one batch, the control group, was hatched naturally by the mother. the second batch, the experimental group, were placed in an incubator with Lorenz being the first large moving object the goslings saw after hatching. the behaviour of each group was recorded. lorenz then marked the goslings so he knew which condition each gosling was in. then he placed them in an upside down box and removed the box and their behaviour was recorded again
• Lorenz 1935 results: lorenz found that straight after birth the naturally hatched goslings followed their mother goose, whereas the incubator hatched goslings followed Lorenz. when the upside box was taken away, the naturally hatched goslings moved immediatlely towards their mother. the incubator hatched goslings followed lorenz showing no attachment to the biological mother. this imprinting occured in a critical period of 4- 25 hours after hatching. this relationship proved to be irreversible
• Lorenz conclusions: these results suggest that imprinting is a form of attachment that is exhibited by birds that typically leave the nest early whereby they imprint onto the first large moving object they encounter after hatching
• harlow (1959) aim - to examine the extent to which contact comfort and food influences attachment behaviour in babu rhesus monkeys
• harlow (1959) method: constructed 2 surrogate mothers: a harsh 'wire mother' and a soft 'towelling mother'. a sample of 16 baby rhesus monkeys were used across four caged conditions; 1. 'wire mother' dispensing milk and 'towelling mother' with no milk 2. 'wire mother' with no milk and 'towelling mother' dispensing milk 3. 'wire mother' dispensing milk 4. 'towelling mother' dispensing milk. the amount of time the baby rhesus monkey spent with each mother and feeding times was recorded. to test the mothers preference during stress, the monkeys were startled with a loud bang.
• harlow (1959) method: also, a larger cage was used in some conditions in order to observe the degree of exploration by the baby rhesus monkeys
• harlow (1959) results: when given a choice of surrogate mothers, the monkeys preferred contact with the towelling monkey even if she wasnt dispensing milk. they would stretch over to the wire mother for food whilst still clinging onto the towelling mother for contacr comfort. the baby monkeys in the condition where it was only the wire mother showed signs of stress. when startled by a loud noise they would cling tightly onto the towelling mother. when the larger cage was used greater exploration was used with the towelling mother showing emotional security
• harlow (1959) results: concluded that baby rhesus monkeys appear to have an innate drive to seek contact comfort from their parent suggesting that attachment is formed through an emotional need for security rather than food, which is contrasting to the learning theory explanation. this contact comfort provided by the mother is associated by a higher willingness to explore their surroundings and lower levels of stress
• a strength of Lorenzs research comes from later research. Guiton replicated the findings of Lorenz with leghorn chicks. Guiton found that leghorn chicks, exposed to yellow rubber gloves for feeding became imprinting on the gloves. also, Guiton found that he could reverse the imprinting in chickens who had initially tried to mate with a rubber glove and that after spending time with their own species, they engaged in normal sexual behaviour. this supports the findings of Lorenz within a different species and suggests that attachment behaviours are innate not learnt
• a criticism of Lorenzs research is his concept of imprinting. the original concept of imprinting is that an image is stamped irreversibly on the nervous system. however, it is now believed that imprinting is more flexible. this shows that young animals are not born with a prediposition to imprint to a specific type of object, but develop their imprinting behaviour to any moving object within a critical window of development. this shows that imprinting is no different from other types of learning and the effects are not irreversible as lorenz originally proposed
• a strength is that Harlows research has important practical applications. it has helped social workers understand risk factors in child abuse and so intervene to prevent it (Howe). we also now understand the importance of attachment figures for baby monkeys in zoos and breeding programmes in the wild. the usefulness of Harlows research increases its value