Newborn
From ChildWiki.com
In the technical definition, newborn refers to a baby that is between birth and 28 days old. After the infant has reached 4 weeks old, they are no longer a newborn. Newborns manage a surprising amount of development and already have quite a few skills in just this short time period.
When a baby is first born, he already knows his mother's voice and scent. Scientists experimented with pads containing the mother's scent on one side of the baby, and someone else's on the other. The newborns reliably turned their heads towards their mothers' scent. In a similar test, they connected the sound of voices to a device that was controlled by the baby sucking on a pacifier, and babies sucked much longer when the voice being played was of their mother.
Within one week a baby can recognize its mother, and can tell the difference between the mother's breast milk and someone else's breast milk. For the first several weeks of life babies can only really focus 10-18 inches away, which is about the distance from a nursing baby to its mother's face. In a test structured the same as the pacifier test above, they showed pictures, and the babies sucked longer for pictures of their mother over pictures of strangers.
Sucking and grabbing are some of the earliest instincts babies have. Sucking is necessary for breastfeeding, but newborns will suck on anything that comes near their mouth, including pacifiers or their own hands. Unfortunately, this can lead to nipple confusion. Thumb sucking normally comes a little later, as newborns don't have the motor skills required to stick their thumb out. Newborns also instinctively grab anything put in their hands. Although newborns are very weak in many ways, they have quite a strong grasp.
