When the baby comes out of the womb, she experiences the first crisis of her life, having been expulsed from a warm and soft embryonic sac, and squeezed through a narrow cavity into a cold, bright room where she will take probably the most difficult breath of her life, exchanging the fluid in their lungs for oxygen.
Now on the outside of her mother's body, the baby's amniotic fluid starts evaporating off her body, lowering her body temperature. Added to that, the bright lights, loud noises, not to mention the loss of the "oceanic feeling" of oneness with her mother's holding environment will make the relief of being placed on mother's chest that much greater. The baby will now seek to achieve the same level of homeostasis she enjoyed in the womb by finding her mother's nipple to satiate her hunger, and alleviating her body's tension through urinating, defacating, coughing, spitting up and sneezing.
From the first moment of skin-to-skin contact, the baby takes in her mother through all the senses. She loves gazing into her mother's eyes and demonstrates a preference for her mother's smell. She responds to her soft cooing voice by turning her head in the direction it's coming from. As the baby learns that her efforts to get the mother's attention are rewarded with warmth, food and a comforting touch, a bond develops between the two. That bond is the subject of John Bowlby and Mary Ainsworth's Attachment Theory, developped in the mid-twentieth century. The quality of an infant's attachment to their mother, they said, sets the stage for their emotional, physical, and intellectual development later in life. A strong symbiosis that includes regular visual and auditory mirroring between mother and the child, creates the conditions whereby the child can begin to feel comfortable separating, exploring, and developping their own relationships.