Animal studies of attachment.
Lorenz’s research
Imprinting… Lorenz observed the phenomenon of imprinting when he was a child and a
neighbour gave him a newly hatched duckling that then followed him around.
PROCEDURE
1. Randomly divided a clutch of greylag goose eggs.
2. Half the eggs were hatched with the mother goose in their natural environment.
3. The other half hatched in an incubator where the first moving object they saw was Lorenz.
FINDINGS
The incubator group followed Lorenz everywhere, but the control group that hatched in the
presence of their mother, followed her instead. When the 2 groups were mixed up, the control
group continued to follow the mother goose, and the experimental group followed Lorenz.
This is called imprinting – where bird species attach to and follow the first moving object they
see.
Lorenz identified a critical period in which imprinting needs to take place – can be only a few
hours but this different depending on the species.
If imprinting doesn’t happen within the critical period, the chicks did not attach
themselves to a mother figure.
Sexual imprinting
Lorenz also observed that birds that imprinted on a human would then want to mate with
humans too. A peacock that had been reared in a zoo imprinted on giant tortoises. As an adult
this bird would only direct mating behaviour towards giant tortoises – the bird had sexually
imprinted.
Harlow’s research
Harlow worked with rhesus monkeys. He observed that newborns kept alone in a bare cage
usually died, and usually survived if given something soft to cuddle.
PROCEDURE
1. Harlow reared 16 baby monkeys with 2 types of wire model ‘mothers’.
2. In one condition there was a bare wire mother that dispensed milk.
3. In the second condition there was a cloth-covered mother who didn’t dispense milk.
Lorenz’s research
Imprinting… Lorenz observed the phenomenon of imprinting when he was a child and a
neighbour gave him a newly hatched duckling that then followed him around.
PROCEDURE
1. Randomly divided a clutch of greylag goose eggs.
2. Half the eggs were hatched with the mother goose in their natural environment.
3. The other half hatched in an incubator where the first moving object they saw was Lorenz.
FINDINGS
The incubator group followed Lorenz everywhere, but the control group that hatched in the
presence of their mother, followed her instead. When the 2 groups were mixed up, the control
group continued to follow the mother goose, and the experimental group followed Lorenz.
This is called imprinting – where bird species attach to and follow the first moving object they
see.
Lorenz identified a critical period in which imprinting needs to take place – can be only a few
hours but this different depending on the species.
If imprinting doesn’t happen within the critical period, the chicks did not attach
themselves to a mother figure.
Sexual imprinting
Lorenz also observed that birds that imprinted on a human would then want to mate with
humans too. A peacock that had been reared in a zoo imprinted on giant tortoises. As an adult
this bird would only direct mating behaviour towards giant tortoises – the bird had sexually
imprinted.
Harlow’s research
Harlow worked with rhesus monkeys. He observed that newborns kept alone in a bare cage
usually died, and usually survived if given something soft to cuddle.
PROCEDURE
1. Harlow reared 16 baby monkeys with 2 types of wire model ‘mothers’.
2. In one condition there was a bare wire mother that dispensed milk.
3. In the second condition there was a cloth-covered mother who didn’t dispense milk.
