Lorenz (1935)
● Aim: to investigate imprinting behaviour in gosling
● Method:
○ Took a clutch of gosling eggs and separated them into 2 groups
○ One left with their mother goose + the other was placed in an incubator - first saw Lorenz
○ The group that saw Lorenz was marked and then all the goslings were placed together
■ Lorenz and the actual mother goose were both present
● Findings:
○ The 2 groups immediately divided themselves
○ Incubator group followed Lorenz everywhere
○ This imprinting happened within a 'critical period' of around 2 days
■ They would imprint on any consistently moving present thing
■ Not all birds imprint on humans
● Conclusion: imprinting is a form of attachment, exhibited mainly by nidifugous birds (ones who have to leave
the nest early), whereby close contact is kept with the first large moving object encountered
● Evaluation AO3:
○ Strength
■ Influential within developmental psychology - imprinting seen to be irreversible suggests that
attachment formation happens within a specific time frame
■ High influential in the way child care is administered
○ Weaknesses
■ Criticised for extrapolation - humans and animals are physiologically different
■ Cannot be generalised
■ Later researchers have questioned the conclusions - Guiton et al (1966) found that chickens
imprinted on yellow washing up gloves would try to mate with them as adults but with
experience they learned to prefer other chickens
■ Suggests that the impact of imprinting on mating behaviour is not as permanent as Lorenz
believed
Harlow (1959)
● Aim: to test learning theory by comparing attachment behaviour in baby monkeys given wire surrogate mother
producing milk with those given a soft towelling mother producing no milk
● method:
○ 2 types of surrogate mothers were constructed
■ A harsh wire mother
■ A soft towelling mother
○ 16 baby monkeys used + 4 in each condition
■ Wire mother producing milk + towel mother no milk
■ Wire mother no milk + towel mother producing milk
■ Wire mother producing milk
■ Towel mother producing milk
○ The amount of time spent with each mother was recorded
○ The amount of time feeding was recorded
○ The monkeys were frightened with loud noises to test for mother preference during times of stress
● Findings:
○ Preferred contact with towel mother when given a choice
■ Regardless of whether she produced milk
○ Monkeys even stretched across to the wire mother to feed while still clinging onto the towel mother -
provided comfort
○ Monkey with only the wire mother suffered from diarrhoea - sign of stress
○ When frightened by a loud noise monkeys clung to the towel mother
○ In the larger cage conditions, monkeys with the towel mother explored more and visited their mother
more