Child

A child is a human being from birth until puberty, or from infancy to the start of puberty. The word can also describe an unborn human. In English-speaking countries, the legal definition of a child is typically a minor—someone under the local age of majority—even if they are physically, mentally, or sexually mature as an adult (though some laws, like those on alcohol, may still apply after that age). Children usually have fewer rights and fewer responsibilities than adults and are generally considered unable to make serious decisions.

The term "child" can also describe a relationship with a parent (sons and daughters of any age) or, metaphorically, a relationship with an authority figure. It can signify membership in a clan, tribe, or religion, or being strongly shaped by a specific time, place, or circumstance, as in "a child of nature" or "a child of the Sixties."

Biologically, a child is a person between birth and puberty. Legally, the term may refer to anyone below the age of majority or another age limit. The United Nations Convention on the Rights of the Child defines a child as anyone under 18, unless national law sets an earlier age of majority; this is ratified by 192 of 194 member countries. Some laws use different age limits: in Singapore, the "Children and Young Persons Act" defines a child as under 14, while the age of majority is 21. In U.S. immigration law, a child is anyone under 21. Some English definitions include the fetus (the unborn). In many cultures, a child becomes an adult after a rite of passage, which may or may not align with puberty. Children generally have fewer rights than adults, are considered unable to make serious decisions, and must always be under the care of a responsible adult or custody arrangement, even if their parents divorce.

Early childhood begins after infancy with toddlerhood, when the child starts speaking or walking independently. Toddlerhood ends around age 3, when the child becomes less dependent on adults for basic needs, but early childhood continues until about age 5 or 6. The National Association for the Education of Young Children includes infancy in early childhood. At this stage, children learn by observing, experimenting, and communicating. Adults supervise and support their development, which leads to autonomy. A strong emotional bond forms between the child and caregivers. Children also start preschool and kindergarten at this age, beginning their social lives.

Middle childhood starts around age 7 and ends around age 9 or 10. Together, early and middle childhood are called the formative years. In this period, children develop socially and mentally, making new friends and gaining skills that increase independence and individuality. They enter school, a new setting that presents new challenges. Mental disorders that might otherwise go unnoticed—such as autism, dyslexia, dyscalculia, and ADHD—often become apparent. Special education, least restrictive environment, response to intervention, and individualized education plans are designed to help children with disabilities. During middle childhood, children begin to understand responsibility and are shaped by peers and parents. They take on chores, make more responsible decisions, and engage in social comparison and social play, learning from and teaching each other through observation.

Preadolescence follows early childhood and precedes adolescence, commonly defined as ages 9–12, ending with the major onset of puberty (markers like menarche, spermarche, and peak height velocity usually occur between ages 11 and 14). It may also be defined as the two years before major puberty onset. Preadolescence brings its own challenges and anxieties. Children at this stage have a more realistic view of life than the fantasy-oriented world of earlier childhood. They have more mature, sensible, and realistic thoughts and actions—often described as the most "sensible" stage of development, with less emotional intensity. They may view human relationships differently, noticing the flawed, human side of authority figures, and begin to develop a sense of self-identity and increased independence, feeling like an individual rather than just part of the family.

Adolescence is usually defined as between the onset of puberty and legal adulthood, mostly corresponding to the teenage years (13–19). However, puberty often begins before the teenage years (around 10–11 for girls and 11–12 for boys).