August 02, 2004
Matt Ridley on either learning it early or not learning it at all
MattRidley.jpgI've been reading Matt Ridley's book Nature Via Nurture: Genes, Experience and What Makes Us Human. (Matt Ridley picture to the right.) Robin McKie, quoted on the back cover, describes it as "A balanced, entertaining gallop through the world of environmental influences and genetic impulses." The relevance of such a book to education and to educators is obvious.

Chapter 6 is entitled "Formative Years", and here is the section from it entitled ""Young Tongues":

Critical-period imprinting is everywhere. There are a thousand ways in which human beings are malleable in their youth, but fixed once adult. Just as a gosling is imprinted with an image of its mother during the hours after birth, so a child is imprinted with everything from the number of sweat glands on its body and a preference for certain foods to an appreciation of the rituals and patterns of its own culture. Neither the gosling's mother-image nor the child's culture is in any sense innate. But the ability to absorb them is.

An obvious example is accent. People change their accents easily during youth, generally adopting the accent of people of their own age in the surrounding society. But some time between about 15 and 25, this flexibility simply vanishes. From then on, even if somebody emigrates to a different country and lives there for many years, his accent will change very little. He may pick up a few inflections and habits from his new linguistic surroundings, but not many. This is true of regional as well as national accents: adults retain the accent of their youths; youths adopt the accent of the surrounding society. Take Henry Kissinger and his younger brother Walter. Henry was born on 27 May 1925, while Walter was born just over a year later on 21 June 1924. They both moved to the United States as refugees from Germany in 1958. Today Walter sounds like an American, whereas Henry has a characteristic European accent. A reporter once asked Walter why Henry had a German accent but he did not. 'Because Henry doesn't listen,' came the facetious reply. It seems more likely that when they arrived in American Henry was just old enough to be losing the flexibility of imprinting his accent on his surroundings; he was leaving the critical period.

In 1967 a Harvard psychologist, Eric Lenneberg, published a book in which he argued that the ability to learn language is itself subject to a critical period that ends abruptly at puberty. Evidence for Lenneberg's theory now abounds on all sides, not least in the phenomenon of Creole and pidgin languages. Pidgins are languages used by adults of several different linguistic backgrounds to communicate with each other. They lack consistent or sophisticated grammar. But once they have been learnt by a generation of children still in their critical period, they change into Creoles – new languages with full grammar. In one case in Nicaragua, deaf children sent to new deaf schools together for the first time in 1979 simply invented a new sign-language Creole of remarkable sophistication.

But the most direct test of the critical period in language learning would be to deprive a child of all language until the age of 15 and then try to teach the poor creature to speak. Deliberate experiments of this kind are thankfully rare, though at least three monarchs – King Psamtik of Egypt in the seventh century BC, the Holy Roman Emperor Frederick II in the thirteenth century and King James IV of Scotland in the fifteenth century – are said to have tried depriving newborn children of all human contact except a silent foster-mother to see whether they grew up speaking Hebrew, Arabic, Latin or Greek. In Frederick's case, the children all died. In a variant on the practice, the Moghul emperor Akbar is said to have done the same experiment to find out whether people were innately Hindu, Muslim or Christian. All he got was deaf-mutes. Genetic determinists were made of stern stuff in those days.

By the nineteenth century, attention had shifted to natural deprivation experiments in the form- of 'feral children'. Two seem to have been genuine. The first was Victor, the wild boy of Aveyron, who appeared in 1800 in the Languedoc having apparently lived wild for many of his 12 years. Despite years of effort, his teacher failed to teach him to speak and 'abandoned my pupil to incurable dumbness'. The second was Kaspar Hauser, a young man discovered in Nuremberg in 1828 having apparently been kept in a single room with almost no human contact for all of his 16 years. Even after years of careful coaching, Kaspar's syntax was still 'in a state of miserable confusion'.

Two suggestive cases, but hardly proof. Then suddenly, four years after Lenneberg's book, there was a third case of a wild child first found after puberty: a 15-year-old girl named Genie was discovered in Los Angeles after a childhood of almost inconceivable horror. The daughter of a blind, abused mother and a paranoid and increasingly reclusive father, she had been kept in silence in a single room, mostly either harnessed to a potty chair or confined in a caged cot. She was incontinent, deformed and almost completely mute: her vocabulary consisted of two words: 'Stopit' and 'Nomore'.

The story of Genie's rehabilitation is almost as tragic as that other childhood. As she was passed between scientists, foster-parents, state officials and her mother (the father committed suicide after her discovery), the initial optimism of those who set out to care for her was gradually spent in lawsuits and bitterness. Today she is in a home for retarded adults. She learned much, her intelligence was high, her non-verbal communication was extraordinary and her ability to solve spatial puzzles was ahead of her age.

But she never learned to speak. She developed a good vocabulary, but elementary grammar was beyond her, and the syntax of word order was a foreign land. She could not grasp how to phrase a question by altering word order or how to change 'you' to 'I' in an answer. (Kaspar Hauser had the same problem.) Though the psychologists who studied her at first believed she would disprove Lenneberg's critical-period theory, they eventually admitted that she was a confirmation of it. Untrained by conversation, the brain's language module had simply not developed, and it was now too late.

Victor, Kaspar and Genie (and there have been other cases, including a woman not diagnosed as deaf until she was 30) suggest that language does not just develop according to a genetic programme. Nor is it just absorbed from the outside world. Instead it is imprinted. It is a temporary innate ability to learn by experience from the environment, a natural instinct for acquiring nurture. Polarise that into either nature or nurture, if you can.

Though language was the most severe of Genie's problems in adjusting to the world, it was not the only one. After her release she became an obsessive collector of coloured plastic objects. She was also for many years terrified of dogs. Both of these characteristics could be tentatively traced to 'formative experiences' in her childhood. Just about the only toys she had were two plastic raincoats. As for dogs, her father would bark and growl outside her door to frighten her if she made a noise. How many of a person's own preferences, fears and habits are imprinted during her youth? Most of us can recall in astonishing detail the places and people of our early years, whereas we forget much more recent adult experiences. Memory is plainly not all critical period – it does not switch off at a certain age. But there is an element of truth in the old notion that the child is father to the man. Freud was right to emphasise the importance of formative years, even if he sometimes generalised too freely about them.

Posted by Brian Micklethwait at 01:49 PM
Category: Science