Lorenz research with geese - imprinting

Aim

1. To investigate the mechanism of imprinting where youngsters follow and form attachment to the first large moving object they meet

2. This process is innate - it is biologically encoded within an animal

Method

1. Decided a number of goose eggs randomly into two groups

2. First half were replaced under their mother - first thing they see is the mother goose ( control group)

3. The other half in an incubator - first thing they saw was Lorenz ( experimental group

4. He marked each group to distinguish them from each other

Dv

Which attachment figure they went to first Lorenz or the mother goose

Findings

1. The goslings quickly divided themselves: the naturally hatched followed their mother and the incubator raised followed Lorenz

2. The incubator group showed no sign of recognition or their natural mother

3. Imprinting has a restricted time period (12-17hours) - critical period.

4. If the birds were not exposed to a moving insect during the critical period then the animals will not imprint.

Conclusion

1. Bird species attach to and follow the first moving object they see.

2. Called imprinting

3. And is a form of attachment

Guiton- supporting evidence for imprinting

1. demonstrate that leghorn chicks exposed to yellow rubber gloves for feeding during the first few weeks became imprinted on the gloves.

2. Young animals are not biologically predisposed to imprint on a specific type of object but probably any moving object that is presented during the critical window of development

3. Also linked to later sexual development as the chicks later tried to mate with the glove.

Imprinting is innate and that it has a specific purpose in development

☹ of imprinting

1. Lorenz argued that imprinting was stamped irreversible on the nervous system and this for many years was accepted view of imprinting

2. However, it is now understood that imprinting is more “plastic” - Hoffman

3. Guiton found that he could reverse the imprinting of the chickens who had initially tried to mate w the yellow gloves.

4. After spending time with their own species they were able to engage in normal sexual behaviours with other chicks