Feral Animal Children: Childhood Trumps Genes

So why don't monkeys, with their legs, arms and hands, act like humans when raised by humans? Because the brain of any animal cannot "think" higher than what it's designed to. Monkeys can be trained by humans to do human things, but this learned behavior results from training. But get this: some predatory animals, when raised from birth by humans, are unable to fend for themselves if released into the wild. Bears exemplify this; when people raise bears from the time they are cute cuddly cubs, those bears must remain in sanctuaries because their predatory survival behavior -- normally taught by their mother -- was never cultivated by their human caretakers during the critical period. Thus, even as adults with all their teeth, claws and power, being released into the wild would assure certain death.

An attempt to see how much a monkey would imprint human behavior was carried out in 1931 when researcher Winthrop Kellogg brought a 7-month-old monkey to live with his wife and their 10-month-old baby. The Kelloggs groomed monkey and baby to be exclusive playmates. Only to a very limited extent did the monkey pick up rudamentary human behavior (such as sitting position and handholding while walking) over a nine-month period. Interestingly, the baby's language development became stunted over the nine months, and the baby began picking up subtle monkey behavior. People who have monkeys as pets will tell you they act like monkeys, though they could "perform" human tricks on command.

The developmental progress of the human brain can be severely impeded by a non-stimulating environment, and because the human brain is the most complex of all animal brains, this downgrading shows the most in humans deprived of stimulation.