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, infant mortality rates measure the deaths during the first year following birth. Similarly in psychology, infancy commonly refers to the first year of life, although the term is sometimes used more loosely to cover the first two or three years of life. In law, infancy as a legal status is typically more extensive, as the young child is usually deemed legally incapable of speaking long after language skills have developed.

Apart from their interest in infant mortality rates, sociologists rarely give much attention to infancy and usually do not treat it as a distinctive period in the life-cycle, subsuming it within the period of childhood. However, there is some sociological interest in psychological research on infant and child development, particularly because of its relevance to controversies about the relative importance of nature and nurture in explaining human behaviour.

Psychologists commonly regard the period of infancy as crucial to individual development and hence to adult behaviour. Sigmund Freud, emphasizing both innate tendencies and social and psychological experience, viewed the first five years of life as determining the individual's subsequent personality and emotional development, and regarded the experiences of the first year as essential to satisfactory ego development—ideas developed more fully by psychoanalytic theorists such as Melanie Klein. Other writers have focused on cognitive development. Jean Piaget's specification of stages of cognitive development, based on his detailed observations, has been especially influential. Recent research on infancy increasingly suggests that infants have considerable cognitive capacities—capacities which selectively regulate their experiences of the environment. See also NATURE VERSUS NURTURE DEBATE.