Attachment studies by Harry Harlow showed that infant monkeys separated from their mothers preferred to cling to a surrogate mother that

While auditory stimuli might have some effect on attraction, Harlow's studies showed that sound alone was not a critical factor in attachment. The preference was not for a surrogate that mimicked motherly sounds, but rather for one that provided physical comfort and warmth.

Although the provision of food is essential for survival, Harlow's findings revealed that it was not the primary factor influencing attachment. The infant monkeys showed a strong preference for the soft surrogate even when the wire mother provided food, underscoring the emotional and psychological aspects of bonding.

Similar to food, water is a fundamental need; however, attachment behaviors in Harlow's experiments were not based on hydration. The soft cloth surrogate was preferred regardless of whether it provided water, highlighting that comfort and nurturing sensations were more significant than merely fulfilling physical needs.

The wire surrogate did provide food, but the stark, unyielding texture of wire lacked the comforting qualities that the infants sought. Harlow's research emphasized that the soft cloth covering was crucial for fostering attachment, indicating that the physical comfort of the surrogate played a more vital role than mere material composition.