Baby Growth and Development Babies grow and develop at a very rapid rate during the first year of life. They grow physically, mentally, emotionally and socially. However, through this portfolio, I intend to discuss the physical growth and development patterns of the infant through their first year. To begin with, development refers to the baby's increased skill in using various body parts. When dealing with the development of a child there are three basic developmental rules. First Developmental Rule: This rule states that babies develop in the head region first, then the trunk, and lastly in the legs and feet. Therefore, it is said