Psychology: Harlow’s experiments on attachment in monkeys. by Janice Fung.

HARLOW’S EXPERIMENTS ON ATTACHMENT IN MONKEYSTHEORIES OF PSYCHOLOGICAL DEVELOPMENT

BACKGROUND• American psychologist Harry Harlow conducted a number

of experiments to investigate the factors influencing the development of attachment by infant rhesus monkeys to their mothers (1958).

• The role of breastfeeding in infant-mother attachment.

WHAT WAS THE AIM?To find out whether provision of food or contact is more important in the formation of infant-mother attachment.

PARTICIPANTS & PROCEDURE• 8 infant rhesus monkeys separated from mothers at birth.

• Monkeys individually reared in cages, each of which contained two surrogate mothers.

PROCEDURESurrogate mothers made of wire mesh, and roughly the same size and shape as real monkey mothers. One surrogate mother covered in terry-towelling cloth, and other left uncovered.

PROCEDUREA feeding bottle was attached to one of the surrogates in the same area where a breast would be for a real mother.

PARTICIPANTS & PROCEDURE

Half of the animals were in cages with feeding bottle on the wire surrogate and the other half were in cages with the feeding bottle on the cloth surrogate.

HARLOW’S HYPOTHESISIf an infant’s attachment to its mother was based primarily on feeding, the infant monkeys should have preferred and become attached to whichever surrogate mother had the bottle.

RESULTSRegardless of which surrogate provided the nourishment, the infant monkeys spent more time with the cloth surrogate than the wire surrogate.

RESULTSBy the age of about three weeks, all of the monkeys were spending around 15 hours a day in contact with the cloth surrogate. No animal spent more than 1-2 hours in any 24-hour period on the wire surrogate.

WHICH SURROGATE MOTHER DID THE MONKEYS PREFER?To test whether the monkeys had preference for the cloth surrogate, Harlow created a stressful condition. Various frightening objects were placed repeatedly in the monkey’s cages.

WHICH SURROGATE MOTHER PREFERRED?Harlow found that the majority of infant monkeys sought first contact with the cloth surrogate, regardless of whether or not it had the feed bottle.

CONCLUSIONHarlow concluded that ‘contact comfort’ (provided by the softness of the cloth covering) was more important than feeding in the formation of an infant rhesus monkey’s attachment to its mother.

WATCH VIDEO: HARLOW’S STUDIES ON DEPENDENCY IN MONKEYS

OTHER ANIMAL EXPERIMENTS BY HARLOW

HARLOW, DODSWORTH, AND HARLOW (1965)• Further experiments found that contact comfort was not

the only important variable in attachment.

• Harlow et. al. (1965) privated a group of rhesus monkeys to prevent them from having any social contact.

• Privation: Removing the opportunity to satisfy a need. In this case, the need for social contact.

HARLOW, DODSWORTH, AND HARLOW (1965)• The monkeys were taken from their mothers just after birth and

totally isolated in cages.

Time of isolation

3 months 6 months 12 months ‘normally reared’(Group 1) (Group 2) (Group 3) (Control group)

What do you think the results were? Think about the case of Genie.

HARLOW, DODSWORTH, AND HARLOW (1965)

Results (read page. 197-198)

Privated from Emotionallysocial contact and socially

impaired

HOW ATTACHMENT IN EARLY LIFE AFFECTS MATERNAL BEHAVIOUR IN THE FUTURE.

• Artificially impregnated the female monkeys that were reared in total isolation for the first 12 months of life (called ‘motherless mothers’).

• Question: What kind of mothers do you think they became?

RESULTS

• Inadequate mothers.

• Consistently avoided her baby, did not appear to care when separated from it.

• Violently abuse baby when baby approached her for feeding.

• Occasionally crushed infant’s face and body to the floor.

• What do you think these results tell us about attachment?

HOW ATTACHMENT IN EARLY LIFE AFFECTS MATERNAL BEHAVIOUR IN THE FUTURE.

ARE THERE ANY ETHICAL ISSUES IN HARLOW’S EXPERIMENTS?

ANIMAL TESTING IN PSYCHOLOGICAL AND MEDICAL RESEARCH. WHAT IS YOUR OPINION?

FOR AGAINST

FOR AGAINST

WHAT ARE SOME ARGUMENTS ON ANIMAL TESTING IN PSYCHOLOGICAL AND MEDICAL RESEARCH.