total of about 10 in. (25.4 cm) in length since birth. Head circumference usually increases about 0.25 in. (0.6 cm) to 0.5 in. (1.3 cm) per month.
Cognitive Development
This is the process by which babies develop the abilities to learn and remember.
Babies begin to recognize and interact with loved ones and start to understand that people and objects still exist even when they are out of sight (object permanence).
Emotional & Social Development
In a loving environment, babies easily bond to their parents. In the first month, newborns express emotion mainly by crying and grimacing or displaying an alert and bright face. By about 4 months, they learn to smile, coo, and move their arms around when excited. By 5 months, babies show a clear preference for a loved one. In the following months, "separation protest" and "stranger anxiety" are some of the ways babies demonstrate this growing attachment. A close bond provides a foundation for future relationships; babies learn how to love and how to trust from their parents.
Language Development
Language development. Babies' brains are very open to learning, and they quickly absorb the language around them. By about 3 to 6 weeks, babies develop a different crying sound to indicate a specific need (such as hunger or discomfort); by around 2 months of age, they begin to interact with caregivers by cooing and smiling, which proceeds to babbling and chuckling within about 6 months. Also by 6 months, most babies have learned all of the basic and distinct sounds of their native language. By the first year most babies can say a few words, like "mama" or "dada," and can understand many more.
Sensory & Motor Development
A baby's movements become more controlled and deliberate as the newborn reflexes fade. Although seemingly stiff at times, a baby will be limber and coordinated enough in 6 months to suck his or her toes and strong enough to sit with light support. By 10 months, many babies can stand, although they may need support.
