Animal studies of attachment: Harlow's research

What did Harlow investigate?

The importance of contact comfort in baby rhesus monkeys which are much more similar to humans than Lorenz’s birds.

What was the procedure of Harlow’s experiment on contact comfort?

Harlow tested the idea that a soft object serves some of the functions of a mother.

He reared 16 baby monkeys with 2 wire model ‘mothers’

In one condition, milk was dispensed by the plain-wire mother whereas in a second condition the milk was dispensed by the cloth-covered mother.

What were the findings of Harlow’s experiment on contact comfort?

The baby monkeys cuddled the cloth-covered mother in preference to the plain-wire mother and sought comfort from the cloth one when frightened regardless of which mother dispensed milk.

What were the conclusions of Harlow’s experiment on contact comfort?

This showed that contact comfort was of more importance to the monkeys than food when it came to attachment behaviour

What else did Harlow investigate?

Harlow followed the monkeys who had been deprived of a ‘real’ mother into adulthood to see if this early maternal deprivation had a permanent effect.

What were the findings of Harlow’s research into maternal deprived monkeys as adults?

The monkeys reared with plain-wire mothers were the most dysfunctional.

BUT, even those reared with a cloth-covered mother did not develop normal social behaviour.

These deprived monkeys were more aggressive, less sociable, bred less, being unskilled at mating, neglected their young and attacked their children.

What was Harlow’s critical period for attachment formation?

A mother figure has to be introduced to a monkey within 90 days for an attachment to form.

After this time, attachment is impossible and damage is irreversible.

What is a strength of Harlow’s research?

Important real-world applications

E.g. it has helped social workers and clinical psychologists understand that a lack of bonding experience may be a risk factor in child development allowing them to intervene to prevent poor outcomes.

This means that the value of Harlow’s research is not just theoretical but also practical.

What is a limitation of Harlow’s research?

You cannot generalise findings and conclusions from monkeys to humans.

Rhesus monkeys are much more similar to humans than Lorenz’s birds and all mammals share attachment behaviours BUT human behaviour is still more complex than monkeys.

This means that it is not appropriate to generalise Harlow’s findings to humans.

What is another limitation of Harlow’s research?

Harlow’s research caused severe long-term distress to the monkeys.