Infants & Toddlers

Infant and toddler development, the physical, emotional, behavioral, and mental growth of children from ages 0 to 36 months.

Different milestones characterize each stage of infant (0 to 12 months) and toddler (12 to 36 months) development. Although most healthy infants and toddlers reach each milestone within a specific window of time, there is much variation as to how wide that window may be. For example, culture, environment, socioeconomic status, and genetic factors can influence when an infant or toddler will begin to crawl, walk, or talk. Children who suffer from undernutrition, who lack social stimuli, or who lack access to proper health care may develop more slowly than children in more enriched environments. Concerns about infant or toddler development arise when milestones are absent or significantly delayed, since such situations may signal an underlying physical or mental condition.