Harry Harlow, an American psychologist, carried out an experiment which changed knowledge about child psychology in 1958. This experiment of placing young rhesus macaques in social isolation showed how attachment to the mother could be decisive in development. primates. His work contributed to the development of the theory of attachment, formalized by the American psychiatrist John Bowlby.

Harry Harlow, an American psychologist and ethologist from the beginning of the 20th century, became known for his experiments in social isolation of young rhesus macaques. This experience, although very cruel, served to demonstrate the importance of accompaniment in the early stages of primate development.

This could then be recognized as a truth in human beings: the attachment to the mother in the early stages of a baby’s development would be essential to his normal psychic development, and be decisive for his future social behavior.

At the time of the experiment, in 1958, it should be noted that little was known about the psychological fragility of babies and young children under 5 years old. It was thought then that they were simply enough food and to meet their basic needs (drinking, sleeping or even doing their needs to grow, without giving more importance to the need for attachment, and also, presence and security. affective or not given to these children Psychological abuse of young children was often observed in orphanages.

Harlow’s methods, referred to as animal torture, have been condemned by many animal advocates. However, at the time, they served to awaken awareness of the mistreatment linked to the isolation of young children, deprived of the love and presence of their parents.

Harlow had decided to verify the attachment theory of which Bowlby was the precursor, by discovering that maternal deprivation had a determining link on the psychological evolution of the young child, until having a mental retardation and a way of attaching emotionally negative.

For this experiment, Harlow used rhesus macaques, an Asian species that lives easily among humans, to study the behavior of babies separated from their mothers.

Harlow placed the babies in cages with two different mother substitutes:

• the first presented herself as a “false mother” in metal, cold, but provided with a bottle of milk;
• the second appeared as a plush looking like an adult macaque, artificially heated, but without a bottle.

The result ofexperience

It was then that Harlow discovered that babies were only going for the stuffed animal, and not the food they needed. They preferred the emotional security, warmth and tenderness that the second mother substitute gave them, sacrificing their need for food for their need for warmth and contact and love.

Harlow then demonstrated the importance, above any other primary need, of the attachment of the baby to its mother when they are still small. The need for contact and warmth would therefore take precedence over the hunger of babies. Satisfying food needs is therefore not essential in establishing a bond between mother and child.

Babies’ need for attachment and bonding with mothers has long been underestimated. The idea, at the time of this experience, was truly revolutionary in the vision of the mother-child relationship: a baby would not only need to eat, drink and sleep to develop, but also and above all to create a bond of warmth, tenderness and love with the mother. This bond provides him with the emotional security that he fundamentally needs.

Harlow was the most famous scientist in this theory, since the experiment he carried out was very controversial, and shocking on several levels: by the new knowledge which it brought in the field of the psychology of the child, but also by the ethical aspect of the experience, very cruel to animals.

This experience enabled John Bowlby and Mary Ainsworth to develop the theory of attachment.

Shortly after Harlow, and following the preliminary papers of 1958, Bowlby expounded the theory of attachment in the three-volume work Attachment and Loss (1969-82 for the original edition, 1978-84 for the French).

In Bowlby’s theory, the child’s interactions with his mother will be decisive for his future relationship life. His first figure of attachment, his mother, will allow him to construct representations of the world and of himself.

In this theory, each has their own unique attachment mode, reflecting our natural preferential mode of interaction with each other. The latter, determined in childhood, no longer evolves into adulthood.

Bowlby, the precursor of this theory, was criticized, however, but his work was completed in the years that followed.