DEPRIVATION
Lack of access to linguistic input in the early years of life– especially in the period up to puberty, which is sometimes said to be a critical period for language acquisition. Deprivation arises when a child is abandoned or is confined in some way which separates them from language. These unfortunate cases enable researchers to explore (a) the extent to which language is innate and develops regardless of adult input; and (b) the hypothesis that it cannot be fully acquired once a particular period of maturation is over.
A well-known instance of a feral child is Victor, the ‘Wild Boy of Aveyron’, found living wild in the French countryside in 1800. Victor’s case was documented by a French doctor, Itard, who attempted to train the boy for human society but recorded very limited linguistic progress. Victor achieved the notion that nouns are used for classes of objects rather than single items and acquired a number of verbs and adjectives, but his syntax remained rudimentary.
There have been a number of more recent cases of attic children. The best documented is that of Genie (USA) who was isolated in a small room from 20 months until 13 years 7 months with no exposure to speech. After she was rescued, she quickly learnt to distinguish speech from other sounds and to recognise recurrent words. She began to speak, though her pronunciation remained idiosyncratic and at times she fell back upon a sign system. She seems, like a normal infant, to have gone through a two-word and a three-word stage, but extended over a much longer period than usual. She acquired a relatively wide vocabulary but her syntactic development remained incomplete. She used few function words and, though some inflectional morphology emerged, it later disappeared. Her use of articles, pronouns, demonstratives and auxiliary verbs was extremely limited. By contrast, her cognitive development was rapid: she progressed by two years of mental age for every year of the study, suggesting a dissociation between general cognition and language. Other cases include:
Isabelle (USA), the child of a deaf mute, rescued from a darkened room at the age of six-and-a-half. A week after rescue, she began to vocalise; her speech acquisition then went through the normal developmental stages but extremely rapidly. Within two years, she had a vocabulary of 2000 words and her language aptitude was comparable to that of other children of her age.
the ‘Koluchova twins’ (Czechoslovakia), rescued from isolation at seven years three months but with a mental age of around three. In a children’s home and later a foster family, they made great cognitive advances and developed above average linguistic skills.
Louise and Mary (UK), rescued and put into care at the ages of three years six months and two years four months respectively. Neither had begun to develop language or social behaviour. Louise went on to achieve normal linguistic competence; but Mary continued to show signs of autism, possibly inherited.
These cases provide tenuous evidence for a sensitive period during which infants are particularly receptive to language. After this period, it seems, vocabulary is acquired but a full syntactic system may not develop.
Important factors seem to be the age at which a child is rescued; the extent to which, on rescue, they show signs of responding to speech; and the opportunity they are given to develop language and cognition through play. Their later linguistic development is strongly assisted by the opportunity to develop normal social and familial relationships.
However, caution has to be exercised in reaching hard-and-fast conclusions. These cases of deprivation do not demonstrate a clear cut-off point at puberty; and later language development seems to vary considerably. More importantly, children who are deprived of language are deprived of affection as well. The trauma of their early experiences may well affect their ability to acquire language. Additionally, some may originally have been neglected by adults because they showed early signs of mental handicap or autism.
See also: Autism, Critical period, Specific language impairment
Further reading: Curtiss (1977); Foster-Cohen (1999: 123–9); Skuse (1993)
