infancy


infancy
/in"feuhn see/, n., pl. infancies.
1. the state or period of being an infant; very early childhood, usually the period before being able to walk; babyhood.
2. the corresponding period in the existence of anything; very early stage: Space science is in its infancy.
3. infants collectively.
4. Law. the period of life to the age of majority, 21 years at common law but now usually 18; minority; nonage.
[1485-95; < L infantia. See INFANT, -CY]

* * *

In humans, the period of life between birth and the acquisition of language usually one to two years later.

The average newborn infant weighs 7.5 lbs (3.4 kg) and is about 20 in (51 cm) long. At birth, infants display a set of inherited reflexes involving such acts as sucking, blinking, and grasping. They are sensitive to light-dark visual contrasts and movements and show a noticeable preference for gazing at the human face; they also begin to recognize the human voice. By 4 months of age most babies are able to sit up, and most begin crawling in 7–10 months; by 12 months most are able to start walking. Virtually all infants begin to comprehend some words several months before they themselves speak their first meaningful words.

* * *

 among humans, the period of life between birth and the acquisition of language approximately one to two years later.

      A brief treatment of infancy follows. For a full treatment of human mental development during infancy, see human behaviour: Development in infancy (human behaviour).

      The average newborn infant weighs 3.4 kg (7.5 pounds) and is about 51 cm (20 inches) long. The newborn gains weight at an average of 170 to 200 g (6 to 7 ounces) per week for the first three months. Growth continues, but the rate gradually declines to an average of 60 g per week after 12 months.

      Newborns typically sleep for about 16–18 hours a day, but the total amount of time spent sleeping gradually decreases to about 9–12 hours a day by age two years. At birth infants display a set of inherited reflexes involving such acts as sucking, blinking, grasping, and limb withdrawal. Infants (sensory reception, human)' vision improves from 20/800 (in Snellen notation) among two-week-olds to 20/70 vision in five-month-olds to 20/20 at five years. Even newborns are sensitive to certain visual patterns, chiefly movement and light-dark contrasts and show a noticeable preference for gazing at the human face; by the first or second month they can discriminate between different faces, and by the third they can identify their mother by sight. Young infants also show a predilection for the tones (hearing) of their mother's voice, and they manifest a surprising sensitivity to the tones, rhythmic flow, and sounds that together make up human speech.

      The ideal food (nutrition, human) for the young infant is human milk, though infant formula is an adequate substitute. Babies can usually be weaned after they are six months old, and the appearance of teeth (tooth) allows them to switch from soft foods to coarser ones by the end of the first year. The first tooth usually erupts at about six months. By the end of the first year, six teeth usually have erupted—four upper incisors and two lower incisors.

      Every normal, healthy infant proceeds through a sequence of motor development (psychomotor learning) that occurs spontaneously and needs no special training. By four months of age the baby can reach for and grasp an object, and by the 10th month he can grasp a small object between thumb and forefinger. By four months most babies are able to sit up for a minute or so without support, and by nine months they can do so without support for 10 minutes or more. Most infants begin crawling between 7 and 10 months, and by 12 months they can stand up alone. The average baby is able to walk with help by 12 months and can walk unaided by 14 months, at which time he is often referred to as a toddler.

      The infant's understanding and mastery of the physical world begins with the reflex movements of newborns. These movements progress within three months to such actions as sucking, grasping, throwing, kicking, and banging, though these are purposeless and repeated for their own sake. During the 4th to the 8th month, the infant begins to repeat those actions that produce interesting effects, and from the 8th to the 12th month he begins coordinating his actions to attain an external goal—e.g., knocking down a pillow to obtain a toy hidden behind it. The infant's physical actions thus begin to show greater intentionality, and he eventually begins to invent new actions in a form of trial-and-error experimentation. By the 18th month the child has begun trying to solve problems involving physical objects by mentally imagining certain events and outcomes, rather than by simple physical trial-and-error experimentation.

      Infants display behavioral (human behaviour) reactions suggestive of emotional states (emotion) as early as the first three or four months of life. The four earliest emotional states they seem to experience are surprise, distress (in response to discomfort), relaxation, and excitement. New emotional states such as anxiety, fear, and sadness have appeared by one year of age. Infants' central emotional feat, however, is probably the establishment of enduring emotional bonds with their parents (parent) or other caregivers. They are biologically predisposed to form such attachments, which in turn form the basis for healthy emotional and social development through childhood (child development). It is through the reciprocal interactions (socialization) between child and parent that the child learns to love, trust, and depend on other human beings. By two months of age, all normal infants show a social smile that invites adults to interact with them, and at about six months of age infants begin to respond socially to particular people to whom they have become emotionally attached.

      Crying is basic to infants from birth, and the cooing sounds they have begun making by about eight weeks progress to babbling and ultimately become part of meaningful speech. Virtually all infants begin to comprehend some words (language) several months before they themselves speak their first meaningful words. By 11 to 12 months of age they are producing clear consonant-vowel utterances such as “mama” or “dada.” The subsequent expansion of vocabulary and the acquisition of grammar and syntax mark the end of infancy and the beginning of child development.

* * *


Universalium. 2010.

Synonyms:

Look at other dictionaries:

  • infancy — in·fan·cy / in fən sē/ n pl cies 1: the legal status of an infant: minority 2: the affirmative defense of lacking legal capacity (as to make a contract or commit a crime) because of being too young and esp. because one s age is below an age set… …   Law dictionary

  • infancy — infancy, infant development Derived from the Latin word infans, meaning ‘unable to speak’, infancy is the earliest period in the human life span, usually taken to extend from birth through to the end of the first year. In demography, for example …   Dictionary of sociology

  • Infancy — In fan*cy, n. [L. infantia: cf. F. enfance. See {Infant}.] [1913 Webster] 1. The state or period of being an infant; the first part of life; early childhood. [1913 Webster] The babe yet lies in smiling infancy. Milton. [1913 Webster] Their love… …   The Collaborative International Dictionary of English

  • infancy — infancy, minority, nonage denote the state or period of being under the age established by law for the attainment of one s full civil rights and independence of guardianship. Infancy is seldom used in this denotation outside of legal documents… …   New Dictionary of Synonyms

  • infancy — (n.) late 14c., from Anglo Fr. enfaunce and directly from L. infantia early childhood, lit. inability to speak, from infantem (see INFANT (Cf. infant)) …   Etymology dictionary

  • infancy — ► NOUN 1) the state or period of early childhood or babyhood. 2) the early stage in the development or growth of something …   English terms dictionary

  • infancy — [in′fən sē] n. pl. infancies [LME < L infantia] 1. the state or period of being an infant; babyhood; very early childhood 2. the beginning or earliest stage of anything 3. Law the state or period of being a minor; period before the age of… …   English World dictionary

  • infancy — noun ADJECTIVE ▪ early ▪ The vaccination is given in early infancy. VERB + INFANCY ▪ survive, survive beyond ▪ Their first child did not survive infancy …   Collocations dictionary

  • infancy — [[t]ɪ̱nfənsi[/t]] 1) N UNCOUNT: usu poss N, prep N Infancy is the period of your life when you are a very young child. ...minute details of Deborah s infancy. ...the development of the mind from infancy onwards. 2) N UNCOUNT: usu in poss N If… …   English dictionary

  • infancy — n. first stage in one s infancy (the industry was still in its infancy) * * * [ ɪnfənsɪ] [ first stage ] in one s infancy (the industry was still in its infancy) …   Combinatory dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.