Harlow's Monkey Experiments: Overview and Findings

Harlow's Classic Monkey Experiments

Overview

  • Conducted by Harry Harlow during the 1950s and 1960s.

  • Focus: To investigate the nature of attachment behavior in infant rhesus monkeys.

Subjects

  • Infant rhesus monkeys were the main subjects of the experiments.

  • These subjects were separated from their biological mothers shortly after birth.

Experimental Setup

  • Two types of 'surrogate mothers' were placed in the cage for the infant monkeys:

    • Wire Mother:

    • Construct: A bare wire frame structure.

    • Function: Equipped with a bottle that dispensed milk.

    • Cloth Mother:

    • Construct: Same shape as the wire mother but covered in soft terry cloth.

    • Function: Did not provide any food.

Key Question

  • The fundamental question posed was:

    • Would the babies cling to the food source (the Wire Mother) or the comfort source (the Cloth Mother)?

Results

  • Observations revealed significant behavior differences:

    • Infant monkeys were seen feeding from the Wire Mother; however, remarkably, they spent around 15 to 18 hours a day clinging to the Cloth Mother.

    • In instances of fear, such as being startled by loud noises or encountering unfamiliar objects, the monkeys consistently sought comfort from the Cloth Mother instead of the food source.

  • Long-term effects on development were noted:

    • Monkeys that were solely raised with the Wire Mother frequently displayed anxiety-driven behaviors.

    • These subjects often grew up to be fearful, socially withdrawn, and faced significant difficulties in mating and caring for their offspring.

Conclusions

  • The experiments demonstrated that physical closeness and affectionate touch are fundamental needs vital for healthy emotional development in infant monkeys.

  • These findings provided evidence that love and emotional security are not just rewards for being fed, but rather essential components for nurturing behavioral and emotional well-being.