Judith Shulevitz examines how loneliness changes the actual genetic makeup of individuals:
[Primatologist Steve] Suomi raises his monkeys in three groups, one group confined entirely to the company of peers (a chaotic, Lord of the Flies kind of childhood); another group left alone with terry-cloth mother-surrogates, except when released for a couple of hours a day to scamper with fellow babies; and the third raised by their mothers. What he found is that, in monkeys separated from their mothers in the first four months of life, some important immunity-related genes show a different pattern of expression. Among these were genes that help make the protein that inflames tissue and genes that tell the body to ward off viruses and other microbes.
“The very fact that something outside the organism can affect the genes like that—it’s huge,” Suomi says. “It changes the way one thinks about development.” I didn’t need genetics, though, to see how defective the peer-raised monkeys’ development had been. Suomi took me outside to watch them. They huddled in nervous groups at the back of the cage, holding tight to each another. Sometimes, he said, they invite aggression by cowering; at other times, they fail to recognize and kowtow to the alpha monkeys, so they get picked on even more. The most perturbed monkeys might rock, clutch at themselves, and pull out their own hair, looking for all the world like children with severe autism.