This updated guide outlines common stages of child development from birth through late adolescence, summarizing motor, cognitive, language, emotional, and social milestones and noting wide individual variation. Caregivers with concerns should consult a pediatrician.
Newborn (Birth)
A newborn can see, hear, and shows primitive reflexes such as sucking and grasping. Babies recognize the human face shape and often show a preference for their mother's voice within days. Early attention focuses on high-contrast patterns and close faces.
0-2 Months
Infants learn to track objects and begin to focus their eyes. The "social smile" - a responsive smile to caregivers - typically appears around 6-8 weeks. Cooing and early vocalizing start as the baby experiments with sounds.
2-6 Months
Emotions become clearer. Babies begin to express pleasure, interest, and discomfort more distinctly. By about 4 months they increasingly reach for and grasp objects; by 6 months many can sit with support and show clearer recognition of familiar people and objects.
6-12 Months
Motor and cognitive skills accelerate. Babies typically develop better depth perception, sit up independently, crawl or scoot, and begin pulling to stand. Object permanence - that hidden objects still exist - emerges in this window, often leading to games like peek-a-boo. Vocal play advances from babbling to sounds that resemble words; many infants say their first recognizable words around 9-12 months.
1-2 Years (Toddlers)
Toddlers walk, run, and explore actively. Language explodes: single words turn into two-word combinations (for example, "more milk"), and comprehension outpaces speech. Emotionally, toddlers show strong attachments and begin to display jealousy and early guilt. Fine motor skills improve: feeding self, stacking blocks, and pointing to pictures.
2-5 Years (Preschool)
Children develop social play, share more easily, and start cooperative games. Language becomes more grammatical and sentences lengthen. Between about 3-4 years children copy shapes and simple letters; by 4-5 years they can draw clearer figures and may write some letters. Imaginative play, growing independence, and stronger friendships characterize this stage.
5-8 Years (Early School Age)
Children refine coordination, learn rules of group play, and start formal reading and math skills. Thinking gradually extends beyond the present to past and future. Peer relationships become increasingly important to social development.
9-15 Years (Adolescence and Puberty)
Puberty brings rapid physical changes and growth spurts. Timing varies widely: girls often start puberty earlier than boys. Emotional and social development intensifies as identity and peer groups take center stage. Girls usually begin menstruation (menarche) roughly 2-3 years after puberty onset; exact timing differs for each child.
15-20 Years (Late Adolescence)
Physical growth slows as individuals reach adult height. The brain continues maturing into the twenties, particularly areas involved in planning, impulse control, and decision making. Social roles and independence increase as teens prepare for adult responsibilities.
Notes on Variation
Children develop at different rates. Milestones indicate typical ranges, not fixed deadlines. If caregivers have concerns about hearing, vision, movement, language, or social skills, they should consult a pediatrician or child development specialist.