Growth and development; human nature

Growth is an increase in height and mass of the body, development is the appearance of new features and abilities. The textbook stages are: newborn period (up to 1 month), infancy (to 1 year), preschool period, school age, then maturity and old age. A baby begins to walk at about one year, and speech develops quickly at 2–4 years. In childhood bones contain much cartilage and are flexible, so sitting straight, not lifting heavy loads, activity and sleep matter. Growth is not even: it speeds up at about 10–12 years in girls and about 12–16 years in boys, and height growth may continue until 20–25; each child’s timing is slightly different, and that is normal. In adolescence (puberty) the body changes under hormones of the endocrine glands, including the sex glands, secondary sexual characteristics appear, and mood may change fast. This is a natural process for everyone; there is no need to compare with peers, and if you have questions about changes, talk to trusted adults or a doctor. For healthy development: a daily routine, sleep (about 8–10 hours), varied food, movement and sport, personal hygiene (daily washing, clean clothes), limited screens, friendship and interesting activities. Do not go on a diet to change body size at your age; if you have questions about eating, see a doctor.