infancy

The Columbia Encyclopedia, 6th ed.

infancy

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 11/2 to 2 years. Thus, as the infant's vocal tract develops, the wider the range of sounds. See voice.

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).

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited article

infancy
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this article
  • Highlights & Notes
  • Citations
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.