infancy


Also found in: Dictionary, Thesaurus, Medical, Legal, Idioms, Wikipedia.
Related to infancy: babyhood

infancy,

stage of human development lasting from birth to approximately two years of age. The hallmarks of infancy are physical growth, motor development, vocal development, and cognitive and social development.

Physical Growth

The first year is characterized by rapid physical growth. A normal baby doubles its birth weight in six months and triples it in a year. During that time, there is great expansion of the head and chest, thus permitting development of the brain, heart, and lungs, the organs most vital to survival. The bones, which are relatively soft at birth, begin to harden, and the fontanelles, the soft parts of the newborn skull, begin to calcify, the small one at the back of the head at about 3 months, the larger one in front at varying ages up to 18 months. Brain weight also increases rapidly during infancy: by the end of the second year, the brain has already reached 75% of its adult weight.

Growth and size depend on environmental conditions as well as genetic endowment. For example, severe nutritional deficiency during the mother's pregnancy and in infancy are likely to result in an irreversible impairment of growth and intellectual development, while overfed, fat infants are predisposed to become obese later in life. Human milk provides the basic nutritional elements necessary for growth; however, in Western cultures supplemental foods are generally added to the diet during the first year.

The newborn infant sleeps almost constantly, awakening only for feedings, but the number and length of waking periods gradually increases. By the age of three months, most infants have acquired a fairly regular schedule for sleeping, feeding, and bowel movements. By the end of the first year, sleeping and waking hours are divided about equally.

Motor Development

Development of motor activity follows a fairly standard sequence. The infant learns to lift its head, to turn over on its back, and to develop the muscular coordination for refined, visually directed hand movements and for sitting, crawling, standing, and walking, generally in that order. Motor development proceeds more rapidly than actual physical growth by the beginning of the second year. Bowel and bladder control is sometimes possible after 18 months. However, many normal, healthy infants show delayed response in one or several developmental activities, or may apparently skip a stage altogether.

Vocal Development

An infant's early crying sounds are largely limited to frontal vowels, such as in "dada," and a few consonants; the remaining vowel and consonant sounds gradually appear, first produced in a babbling manner, and the first meaningful words may appear at ten months. By the end of the second year, the infant's active vocabulary may reach 250 words. One of the key reasons infants can produce more sounds is the developing larynx, or voice box, which "descends" between the ages of 1 1-2 to 2 years. Thus, as the infant's vocal tract develops, the wider the range of sounds. See voicevoice,
sound produced by living beings. The source of the sound in human speaking and singing is the vibration of the vocal cords, which are inside the larynx, and the production of the sounds is called phonation.
..... Click the link for more information.
.

Cognitive and Social Development

Studies indicate that certain cognitive processes, the order of which is largely biologically controlled, begin as early as two months after birth. Up to six months of age, differences in motor and conceptual development are generally independent of the infant's rearing conditions and culture, but by one year of age, cultural differences affect intellectual development. From the early months on, the infant forms attachments to those who care for him or her, and on the basis of their behavior, begins to develop expectations of gratification, e.g., adult responses to cries of distress. Social smiling appears early, and by the latter part of the first year the baby may depend on the presence of familiar faces and become apprehensive in the presence of strangers.

Bibliography

See the many studies by child psychologist J. Piaget; J. Kagan et al., Infancy: Its Place in Human Development (1978); T. B. Brazalton, Infants and Mothers (rev. ed. 1983); J. G. Bremner, Infancy (1988).

infancy

[′in·fən·sē]
(geology)
The initial (youthful) or very early stage of the cycle of erosion characterized by smooth, nearly level erosional surfaces dissected by narrow stream gorges, numerous depressions filled by marshy lakes and ponds, and shallow streams. Also known as topographic infancy.

infancy

the period of life prior to attaining legal majority (reached at 21 under common law, at 18 by statute); minority nonage
References in periodicals archive ?
'We are left with the difficulty, as in so many such deaths in infancy, that from the pathological findings, the cause of death remains unascertained.
The finding suggests that GERD appears to be a chronic condition that starts in infancy and is not always outgrown by age 3 or 4 years as previously believed.
A group of apocryphal writings, called the "Infancy Gospels," expand on the missing years.
Being Slovakia's first neuropsychiatrist, he is aware that his field, well-established abroad but still in its infancy in Slovakia, requires a basic introduction."It is a small miracle that neuropsychiatry found its way to Slovakia because even a relatively big part of the academic community does not understand what it's about," he told The Slovak Spectator.
Many Roman Catholics traditionally observe the month of December as Divine Infancy Month in honor of the Child Jesus, "the center of all preparations and celebrations during the Christmas Season."
Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, rapidly growing, pigmented neoplasm of neural crest origin first described in 1918, (1) with slightly more than 500 reported cases to date.
MONDAY, April 2, 2018 (HealthDay News) -- The use of acid-suppressive medications and antibiotics during the first six months of infancy is tied to subsequent development of allergic disease, according to a study published online April 2 in JAMA Pediatrics.
The image also referred, more generally, to the childhood of all people, who are born not equipped with language, but "in a circle in which infancy is the origin of language and language the origin of infancy," as Giorgio Agamben observes in his 1978 book Infanzia e storia: Distruzione dell'esperienza e origine della storia (Infancy and History: Essays on the Destruction of Experience).
Psychologist Professor Vincent Reid said the research, published in the journal Neuropsychologia, showed a link between perceiving an action and carrying out that action even in early infancy. He added that this result strongly suggests that experience refines the perception of biological motion during early infancy.
Melanocytic neuroectodermal tumor of infancy (MNTI) is a rare osteolytic neoplasm of neural crest cell origin most frequently found in infants less than 1 year old [1].
An ossifying renal tumor of infancy (ORTI) is an extremely rare finding, with only 24 published cases in the literature to date [1-3].
The Idea of Infancy in Nineteenth-Century British Poetry: Romanticism, Subjectivity, Form.