Recent research in epigenetics is suggesting that the way in which genes express themselves depends on the environment in which they operate. Evidence for this appeared in 1797 when three hunters near Saint-Sernin-sur-Rance in France sighted a young pre-pubescent male sprinting through the woods. They gave chase and captured him when he attempted to escape by climbing a tree. The feral youth was brought into town where a widow took him into her home. Since he was unable to speak and showed the kind of social detachment that we associate today with autism, no one was surprised when he escaped back to the woods. However, there were reported sightings of him by villagers during the next two years until, on January 8, 1800, at an estimated age of 12, he emerged from the woods and came into the village.
After a series of informal adoptions and escapes, the strange “wild boy of Aveyron,” later named “Victor,” encountered a young medical student, Jean Marc Gaspard Itard, who housed him and set about teaching him to speak. Though Victor showed some progress in acquiring language, he was unable to read more than a few simple words, and he never reached a level where he could communicate beyond basic grunts. The boy of Aveyron, was born with a capacity for language, yet his isolated environment had prevented him from learning to speak by age 12, leaving him incapable of subsequently developing linguistic capability.
A similar case arose in 1970, when a girl nicknamed, “Genie” was found imprisoned in a Los Angeles home. She had been confined from birth to a locked room and subjected to beatings whenever she made a noise. The only sounds she heard were muffled by the confining walls of her prison. When rescued at age 13, it was discovered that she had no speech capability. Four years of speech therapy and sign language training enabled her to develop a very limited vocabulary, pairing words with objects, but she could not formulate sentences. The deprivation of speech stimulation had resulted in a neural pruning that removed her capacity for language. Even years of rehabilitation, could not repair the irreversible damage done by her sensory deprivation.
During our formative years, our braIn enters periods of prodigious neural generation, followed by periods when unused neural functions are purged. A lack of stimulation of neural functions, like speaking, during key periods in our formative years permanently closes a window on that neural function. This explains why people who learn a new language after the age of 12 or 13, usually speak that language with an accent.
