A baby is unable to discharge his own energy when he is on his back looking at the ceiling or the inside of a stroller bonnet. When carried in an sling, the baby shares in your walking, talking, working, laughing, playing, and is able to discharge that energy in the most pleasurable way. Studies with monkeys have shown that those deprived of touch have more difficulty coping with stress than those who are held.
Stress is known to cause disease in humans.
Carried babies see and experience the world, they participate with their parents, develop their senses faster, cry less, learn more, and thrive better because they are less bored and more relaxed and secure. Carrying infants in a sling not only reduces irritability, but protects them from too much environmental stimuli. According to Do. Brazelton, each infant has an individual threshold for stimulus which can be used for organization and learning. Stimulation that exceeds this threshold overloads the infant and sets up defenses which are likely to be costly to future development.