Topic 4: Animal studies Lorenz and Harlow

Lorenz Imprinting procedure

-Lorenz divided a clutch of eggs in two halves. One half was left to hatch with the mother(control group)

- The other half hatched in an incubator, the first moving thing they saw was lorenz

Results of lorenz imprinting

- The control group followed their mother goose everywhere whereas the second group followed lorenz

- He marked the goslings to indicate which group of eggs they hatched from and let them out together from an upturned box. Each gosling went straight to is mother figure. Lorenz goslings showed no recognition of their real mother.

What is imprinting?

This is when birds who are mobile after birth, follow and attach to the first moving object that they see.

What is the critical period?

This is the time which imprinting must take place.

Lorentz and sexual imprinting

● Lorenz found that whatever the bird imprinted on it would direct its sexual behaviour towards that object when they got sexually mature.

● Lorenz described the case of a peacock that attached to giant tortoises. As an adult they would direct courtship behaviour towards them.

Lorenz AO3

☹️ Difficult to generalise to humans. Attachment in mammals is very different to birds. Mammalian mothers show more emotional attachment to their young than birds and mammals can form attachments at any time.

☹️ Lorenz's Observations have been questioned. Guiton found that chickens imprinted on yellow washing up gloves would try to mate with them as adults. However, with experience they would prefer to mate with other chickens.

● This suggests that imprinting is not as permanent as lornz believed.

Harlow: effects of privation procedure

- 16 rhesus monkeys were separated immediately after birth and placed in a cage with a mother made of wire and one covered in soft terry towelling cloth

1. Eight of the monkeys could get milk from the wire mother. 2. Eight could get milk from the cloth mother

Harlow: effects of privation results

- Both groups of monkeys spent more time with the cloth mother(even if she had no milk)

- The infants of the second group would only go to the wire mother when hungry then return to the cloth mother for most of the day

- If a frightening object was placed in the cage , the infant took refuge with the cloth mother. The infant would explore more when the cloth mother was present

Describe Harlow's additional study

- He observed the difference between the monkeys who grew up with normal mothers and the monkeys who grew up with surrogate mothers.

- They were much more timid, they didn't know how to behave with other monkeys, they had difficulty with mating and the females were inadequate mothers.

- For those who were with the mother for less than 90 days the effects could be reversed if placed in a normal environment where they could form attachments

Describe Harlow's conclusion of his study

- Harlow concluded that contact comfort provided by the cloth mother was more important than food in the formation of attachment.

- He also concluded that early maternal deprivation leads to emotional damage, but its impact could be reversed if an attachment was made before the end of the critical period.

- However if maternal deprivation lasted after the end of the critical period then no amount of exposure to mothers could alter the emotional damage

Harlow's AO3

- Harlow's findings have had a profound effect on psychologists understanding of human mother-infant attachment. He showed that attachment is a result of contact comfort. This has led to practical applications.

- However Harlow received criticism because of the suffering that was caused to the animals