I found the answer in studies of cases where children had been isolated since a young age and grew up either confined or roaming the wilds. EVERY ONE LACKED language. Not only did they lack language, they were never able to acquire it in its true sense, but learned only a few hundred words useful to them, much like the apes taught to use sign language or computer logograms. And their behavior? They were not autistic, not lost in an imagined world, but incredibly alert to their environment and able to survive incredible challenges--rainforests, mountains, predators and finding food. And they behaved like any other animal. They were notably selfish, and could act violently but without sadism. The most fascinating stories were those of Amala and Kamala, the Wolf girls of India, the boy of Aveyron, but especially that of Zana, whom some imminent scientists believe may have been an extraordinary case of the last surviving Neanderthal who lived in the Caucasus mountains of central Asia!