Psychological Development Across the Lifespan
What are the major developmental milestones in the first year?
More development happens in the first year of life than at any other time after birth. During the first year, the body almost triples in weight and becomes about one-third longer. Moreover, a newborn is unable to talk, crawl, move independently, or even hold his or her head up. By the end of the first year, the typical child can crawl, manipulate objects, and is beginning to walk and talk. In fact, much of human development in the first year of life happens before birth in other species. For example, horses and deer are ready to walk immediately after birth.
The major milestones in the first year of life include the social smile (two months), laughter (four months), the ability to sufficiently coordinate vision and grasp to play with an object (four months), the ability to sit up (six months), the ability to eat solid food (eight months), the ability to crawl (seven months), the ability to pull oneself up to a standing position (ten months), the ability to walk independently (twelve months), and the formation of words (twelve months).