randomly divided goose eggs into two groups, a control and experiment group.
the control group hatched with the mother goose in a natural environment and the experimental group hatched in an incubator where Lorenz was the first moving object
completed experiment again where a peacock imprinted on a tortoise at birth and showed signs of courtship towards tortoises - sexual imprint
Lorenz results:
experimental group followed Lorenz everywhere, control group followed mother
when the groups were mixed, they followed their correct caregiver
concluding that humans have a critical period where they create attachments with people - so do animals, otherwise they struggle to form attachments with anything
imprinting: where someone forms an attachment with the first thing that they see
Lorenz evaluation:
strength:
Bowlby; suggested that animals and humans both have critical periods where they form attachments
weakness
ungeneralisable to humans as animal attachments are different to human attachments
Harlow (1958): separated monkeys from their months and kept them in cages
eight monkeys studied with a wire 'mother' and a cloth 'mother'
condition 1: milk was dispensed by the plain wire mother
condition 2: no milk was dispensed by the cloth covered mother
Harlowfindings:
monkey would spend more time on the cloth covered mother - increased when it became frightened by mechanical toy
monkeys more willing to explore a room with toys when cloth covered mother was present
concluding: love and affection is essential as without it, it becomes increasingly difficult for them to establish attachment
Harlow evaluation:
strength:
cannot perform this on humans - can refer it to feral children as their development is delayed and cannot be improved
weakness:
generalisation of monkeys to humans is complex as they are a different species
distress caused long-term consequences on their development and can be deemed unethical