Who emphasized the importance of physical contact comfort in attachment?

The emphasis on physical contact comfort in attachment is most notably associated with Harlow, particularly through his experiments with rhesus monkeys. Harlow's research demonstrated that infant monkeys preferred to cling to a soft, cloth-covered surrogate mother rather than a wire mother that provided food. This finding illustrated that comfort and security derived from physical contact were crucial for the development of attachment. Harlow's work was groundbreaking in showing that emotional bonds can be more strongly associated with nurturing and comfort than with the provision of basic needs, challenging previous notions of attachment that were primarily based on feeding. His research has had lasting implications in the understanding of attachment theory in both animals and humans.