Animal Studies Of Attacment Flashcards
Who carried out the 2 key animal studies / outline
Lorenz
Harlow
They are interested in the formation of early bonds between non-human parents and their offspring.
What is imprinting
when a new born baby (animal or human) attaches to the first living thing they see at birth – this happens very soon after birth and in a specific time frame (critical period). If imprinting does not occur within this critical period, then the baby will probably never be able to form an attachment!
Imprinting research - lorenz
Aim – to investigate the mechanisms of imprinting where the youngsters follow and form an attachment to the first large moving object that they meet.
Procedure -
Lorenz split a large clutch of greylag goose eggs into two batches, one of which was hatched naturally by the mother and the other hatched in an incubator, with Lorenz making sure he was the first moving object the newly hatched goslings encountered. Once hatched the behaviour of the goslings was observed and recorded.
Lorenz then marked all of the goslings so he could determine whether they were from the naturally hatched batch of eggs or the incubated ones, and placed them under an upturned box. The box was then removed and following behaviour was then recorded
Evaluation of Lorenz’s research
There are a number of other studies that have demonstrated imprinting in other species of birds `too thus supporting Lorenz’s research on imprinting. For example, Guiton (1966) demonstrated that leghorn chicks, exposed to yellow rubber gloves for feeding them during their first few weeks, became imprinted on the gloves. Guiton also found that the male chickens later tried to mate with the gloves!
Furthermore, in a case study Lorenz (1952) described a peacock that had been reared in the reptile house of a zoo where the first moving objects the peacocks saw after hatching were giant tortoises. As an adult this bird would only direct courtship behaviour towards giant tortoises. Lorenz concluded that this meant he had undergone sexual imprinting
However, there is some dispute over the characteristics of imprinting. The original concept imprinting, than an encounter with an appropriate object leads to the image of that object being somehow stamped irreversibly on the nervous system was the accepted view of imprinting. Now it is understood that imprinting is a more ‘plastic and forgiving mechanism’ (Hoffman, 1996) and can be reversed as was shown by Guiton (1966) who found that the chicken’s behaviour towards mating with the yellow gloves could be reversed after spending time with their own species.
Also, Lorenz was interested in imprinting in birds, and thus there is a problem of generalising from birds to humans as it seems that mammalian attachment system is quite different from birds – for example, mammalian mothers show more emotional attachment to young than do birds, and mammals may be able to form attachments at any time rather than a specific critical period (although this has been debated).
Harlow research
Harlow used rhesus monkeys to see if attachments are primarily formed through food as explained by the Learning Theory. New born monkeys were separated from their mothers and raised in cages. In each cage was a ‘baby blanket’ and the infant monkeys became distressed whenever the blanket was removed, a similar reaction to when baby monkeys are separated from their mothers. This suggested that attachment was not based on association with food.
Aim – to test learning theory by comparing attachment behaviour in baby monkeys given a wire surrogate mother producing milk with those given a soft towelling mother given no milk.
Procedure – Two types of surrogate mother was constructed – a harsh ‘wire mother’ and a soft ‘towelling mother’. Sixteen baby monkeys were used, four in each of four conditions:
1. A cage containing a wire mother producing milk and a towelling mother producing no milk.
2. A cage containing a wire mother producing no milk and towelling mother producing milk.
3. A cage containing a wire mother producing milk.
4. A cage containing a towelling mother producing milk.
The amount of time spent with each mother, as well as feeding time was recorded. The monkeys were frightened with a loud noise to test for mother preference during stress.
A larger cage was also used to test the monkeys’ degree of exploration.
Evaluation of Harlows Research
One strength of Harlow’s research into attachments is its theoretical value – Harlows findings have had a profound effect on psychologists understanding of human- infant attachment – most importantly Harlow’s research showed that attachment does not occur due to being fed by a mother figure – rather attachment is due to contact comfort. Harlow also showed the importance of the quality of early relationships for later social development – including the ability to hold down adult relationships and successfully rear children. In other words the importance of the internal working model.
Another strength of Harlow’s research into attachments is its practical value – Harlow’s research has had important practical applications for example, it has helped social workers understand risk factors in child neglect and abuse and so intervene to prevent it (Howe, 1998). Furthermore, these findings are also important in the care of captive monkeys in zoos and in breeding programmes in the wild whereby it is necessary for the need of proper attachment figures for baby monkeys and how not to separate the baby from it’s mother! Therefore it could be argued that the benefits outweigh the costs to the animals involved in the study.
One weakness of Harlow’s research into attachment are the ethical issues – a study such as Harlow’s could not be done with humans, but there is also the question of whether it should be done with monkeys. The study created lasting emotional harm as the monkey’s later found it difficult to form relationships with their peers. In fact Sackett (2002), a student of Harlow’s, believes that Harlow’s research was so unjustifiably unethical that the American animal Liberation movement was born out of it. Many of the monkeys in his experiments died!
Another weakness of Harlow’s research into attachments is the problems of generalisation of animal studies to humans – The ultimate aim of animal studies is to be able to generalise the conclusions to human behaviour. However animal studies have issues of generalisation to human behaviour mainly because humans behaviour is governed by conscious decisions and we are not able to attain how animals make their decisions. However, the fact the animals do not bond with the person who feeds them (as was shown in Harlow’s study) was also shown in Schaffer and Emerson’s study so animal studies can act as a useful pointer in understanding human behaviour. However we should still seek confirmation by looking at research with humans too.
lorenz findings
Finding – Immediately after birth, the naturally hatched baby goslings followed their mother about, while the incubator hatched goslings followed Lorenz around.
When released from the upturned box, the naturally hatched goslings went straight to their mother, while the incubated goslings went to Lorenz, showing no bond with their natural mother. These bonds proved to be irreversible; the naturally hatched goslings would only follow their mother and the incubated ones would only follow Lorenz.
Lorenz also noted how imprinting would only occur within 4 and 25 hours after hatching (critical period) otherwise it would not occur at all.
Sexual Imprinting
Lorenz also investigated the relationship between imprinting and adult mate preferences. He observed that birds that imprinted on a human would often later display courtship behaviour. Lorenz (1952) noted several features of imprinting, for example that the process is irreversible and long lasting. Lorenz described how one of the geese who imprinted on him called Martina, used to sleep on his bed every night (and may have even tried to mate with him!).
harlow findings and show what they suggest
Findings
Monkeys preferred contact with the towelling mother when given a choice of surrogate mothers, regardless of whether it produced milk, they even stretched across to the wire mother to feed while still clinging to the towelling mother.
Monkeys with only a wire surrogate had diarrhoea, a sign of distress.
When frightened by a loud noise, monkeys clung to the towelling mother in conditions where she was available.
In the larger cage conditions, monkeys with towelling mothers explored more and visited their surrogate mother more often
Conclusions
Rhesus monkeys have an innate, unlearned need for contact comfort, suggesting that attachment concerns emotional security more than food.
Contact comfort is associated with lower levels of stress and a willingness to explore, indicating emotional security
In another study, Harlow et al. (1965) raised newborn monkeys in total isolation from other living beings for 3, 6, 12 or 24 months. These monkeys displayed signs of psychological disturbance, hugging their own bodies and rocking repetitively.
When eventually placed with other monkeys they were fearful of them and had no social interaction, other than to attack them. They also harmed themselves, biting their arms and legs and pulling out their hair. The degree of damage correlated positively with the amount of total isolation a monkey had endured. These monkeys, when adult, seemed to have no ability to engage in sexual courtship.
Harlow keen to see how they would cope as parents, devised an apparatus he called a ‘rape rack’ to which female monkeys raised in isolation would be tied and forcibly mated. As parents, they were awful, abusing and neglecting their babies; one mother chewed off her own baby’s feet and fingers whilst another crushed her baby’s head to a pulp.
The findings suggest that social interactions are essential for normal social and emotional development to occur.
Furthermore, Harlow and Suomi (1972) raised four newborn male monkeys in total isolation for 6 months and then placed each one with a normally raised three- month old female ‘therapist’ monkey for two hours three times a week, gradually increasing the amount of contact time. After twelve months their behaviour was almost normal and by three years of age they had totally recovered and were able to live among normally raised monkeys. This suggests that the effects of total isolation are reversible.
