Animal Studies

Lorenz 1935 Procedure

Took a clutch of gosling eggs and divided them into two groups. One group left with natural mother, one group put into an incubator.

When incubator eggs hatched, first living, moving thing they saw was Lorenz and they soon started following him.

To test effect of imprinting, Lorenz marked the two groups to distinguish them and placed them together.

Lorenz 1935 Findings

Found that the goslings quickly divided themselves up, one followed them natural mother and the other followed Lorenz. Lorenz’s brood showed no recognition of the natural mother. He noted that imprinting is restricted to a very definite period of time called the critical period.

If a young animal is not exposed to a moving object during this early critical period the animal will not imprint.

Lorenz Long Lasting Effects

Process is irreversible and long lasting. Example of Martina the goose who slept on Lorenz’s bed every night.

Early imprinting has an affect on later mate preferences, called sexual imprinting. Animals (especially birds) will choose to mate with the same kind of animal they had imprinted on.

Harlow Proceure

Harlow created two mothers each with a different ‘head’. One mother was covered in cloth.

Eight rhesus monkeys were studied for 165 days. Four of the monkeys were fed by the wire mother, four by the cloth mother.

Observations were made on the amount of time the infant spent with their mother as well as their responses when frightened by the mechanical teddy bear.

Harlow Findings

All eight monkeys spent most of their time with the cloth mother whether or not it was the mother that fed them. Monkeys fed by the wire mother only spent time with it for food.

When frightened, all monkeys clung to the cloth mother and when playing, the infants left one foot on the cloth mother for reassurance.

These findings suggest contact comfort is more influential than feeding.

Harlow Long Lasting Effects

Harlow continued to study the monkeys and noted the consequences of their early attachment experiences. All monkeys developed abnormally. They froze or fled when approached by other monkeys and were sexually abnormal- not showing typical mating behaviour and not cradling their own babies.

Like Lorenz, Harlow also found a critical period. If the motherless monkeys spent time with their monkey ‘peers’ before three months they seemed to recover. Having more than six months with only a wire mother had irreversible effects.

AO3 Research Support for Imprinting

There is research support for Lorenz’s theory of imprinting in animals.
Guiton (1966) found that leghorn chicks exposed to yellow rubber gloves while being fed became imprinted on the gloves. This shows that young animals are not born with a predisposition to imprint on a specific object but are likely to imprint on any moving object encountered during a critical period.
Guiton also found that the male chicks later attempted to mate with the gloves, suggesting that early imprinting is linked to later reproductive behaviour.
This provides clear support for Lorenz’s original research and strengthens the validity of his conclusions about imprinting.

AO3 Criticisms of Imprinting

There is some dispute over the characteristics of imprinting.
For many years, imprinting was believed to be an irreversible process, where the attachment object became permanently fixed. However, more recent research suggests imprinting is a more plastic and reversible process (Hoffman, 1996).
Guiton (1966) found that although chicks initially tried to mate with gloves, after spending time with their own species they were able to engage in normal sexual behaviour.
This suggests that imprinting may not be as permanent or unique as Lorenz claimed and may not be so different from other forms of learning, which can also occur quickly and be reversible.

AO3 Threat to Validity

One criticism of Harlow’s research is that the two stimulus objects used in the study differed in more ways than just whether they were cloth-covered or wire.
The cloth mother was not only soft but also had a more realistic head and face, which acted as a confounding variable. This means there was an additional variable that could have influenced the dependent variable (time spent with each mother).
As a result, it is unclear whether the monkeys spent more time with the cloth mother because of contact comfort or because she appeared more realistic.
This lack of control reduces the internal validity of the study, as a clear cause-and-effect relationship cannot be established, weakening the conclusions drawn from the research.

AO3 Generalising animals studies to human behaviour

Humans differ from animals in important ways, particularly because much more of human behaviour is influenced by conscious thought, culture, and social factors.
This means that attachment behaviour observed in animals may not fully represent the complexity of human attachment relationships.
However, some research has found similarities between animal and human attachment. For example, Quinton et al. (1984) found that women who experienced poor attachment as children struggled to parent their own children, mirroring Harlow’s findings.
This suggests that while animal studies can provide useful insights into attachment, conclusions should always be confirmed using research with humans.