mysterious,” she said. “But at some point, what you’re seeing is just a complex series of chemical reactions. It’s the folding of a protein or the activation of a neuron. And what’s exciting about that is that those things are treatable. When you get down to the molecules, you realize, that’s where the healing lies. That’s where you’re discovering a solution.”
Burke Harris told me the story of one particular patient, a teenage boy who, like so many of her patients, lived in a stress-filled home that had inflicted on him a particularly high ACE score. She had run her clinic long enough that she had essentially been able to watch him grow up. When he first came to the clinic, he was ten, an unhappy child in an unhappy family but still a boy, someone who had withstood some blows but who still seemed to have a chance to escape his bleak destiny. But now this boy was fourteen, an angry black teenager on his way to being six feet tall, and he was hanging out on the street, getting into trouble—a hoodlum in training, if not a criminal already. The reality is that most of us are inclined to feel nothing but sympathy and understanding toward the ten-year-old—he is a boy, after all, and clearly a victim. But toward the fourteen-year-old—not to mention the eighteen-year-old he will soon become—we usually feel something darker: anger and fear, or at least despair. What Burke Harris could see, of course, with the advantage of time and with her clinician’s perspective, was that the ten-year-old and the fourteen-year-old were the same child, reacting to the same environmental influences, buffeted by the same powerful neurochemical processes.
Spending time with the kids in YAP, I often found myself wrestling with questions of guilt and blame: When does the innocent boy become the culpable man? I had no objection to the proposition that aggravated vehicular hijacking is a genuinely bad thing, and that people who do it, even sensitive, thoughtful guys like Mush, should suffer the consequences. But I could also see Steve Gates’s point of view: that these were young men caught in a terrible system that constrained their decisions in a way that was almost impossible for them to withstand. Gates defined that system mostly in social and economic terms; Burke Harris saw it neurochemically. But the more time I spent in Roseland, the more those two perspectives seemed to converge.
9. LG
Much of the new information about childhood and poverty uncovered by psychologists and neuroscientists can be daunting to anyone trying to improve outcomes for disadvantaged children. We now know that early stress and adversity can literally get under a child’s skin, where it can cause damage that lasts a lifetime. But there is also some positive news in this research. It turns out that there is a particularly effective antidote to the ill effects of early stress, and it comes not from pharmaceutical companies or early-childhood educators but from parents. Parents and other caregivers who are able to form close, nurturing relationships with their children can foster resilience in them that protects them from many of the worst effects of a harsh early environment. This message can sound a bit warm and fuzzy, but it is rooted in cold, hard science. The effect of good parenting is not just emotional or psychological, the neuroscientists say; it is biochemical.
The researcher who has done the most to expand our understanding of the relationship between parenting and stress is a neuroscientist at McGill University named Michael Meaney. Like many in the field, Meaney does much of his research with rats, as rats and humans have similar brain architecture. At any given time, the Meaney lab houses hundreds of rats. They live in Plexiglas cages, and usually each cage holds a mother rat, called a dam, and her small brood of baby rats, called pups.
Scientists in rat labs are always picking up baby rats to examine them or weigh them, and one day about ten years ago, researchers in Meaney’s lab noticed a curious thing : When they put the pups back in the cages after handling them, some dams would scurry over and spend a few minutes licking and grooming their pups. Others would just ignore them. When the researchers examined the rat pups, they discovered that this seemingly insignificant practice had a distinct physiological effect. When a lab assistant handled a rat pup, researchers found, it produced anxiety, a flood of stress hormones, in the pup. The dam’s licking and grooming counteracted that anxiety and calmed down that surge of hormones.
Meaney and his researchers were intrigued, and they wanted to learn more about how licking and grooming worked and what kind of effect it had on the pups. So they kept watching the rats, spending long days and nights with their faces pressed up against the Plexiglas, and after many weeks of careful observation, they made an additional discovery: different mother rats had different patterns of licking and grooming, even in the absence of their pups’ being handled. So Meaney’s team undertook a new experiment, with a new set of dams, to try to quantify these patterns. This time, they didn’t handle any of the pups. They just closely observed each cage, an hour at a time, eight sessions a day, for the first ten days of the pups’ lives. Researchers counted every instance of maternal licking and grooming. And after ten days, they divided the dams into two categories: the ones that licked and groomed a lot, which they labeled high LG, and the ones that licked and groomed a little, which they labeled low LG.
The researchers wanted to know what the long-term effects of these variations in parenting behavior might be. So when the pups were twenty-two days old, they were weaned, separated from their mothers, and housed for the rest of their adolescence with same-sex siblings. When the pups were fully mature, about a hundred days old, Meaney’s team gave them a series of tests that compared the offspring of the high-licking-and-grooming dams with the rats that hadn’t received a lot of licking and grooming as pups.
The main evaluation they used was something called an open-field test, a common procedure in animal- behavior studies: A rat is placed in a large, round, open box for five minutes and allowed to explore at will. Nervous rats tend to stay close to the wall, circling around and around the perimeter; bolder rats dare to venture away from the wall and explore the whole field. In a second test, designed to measure fearfulness, hungry rats were placed in a new cage for ten minutes and offered food. Anxious rats, like jittery guests at a fancy dinner party, tend to take longer to work up the nerve to try any food, and they eat less than the calmer, more confident rats do.
On both tests, the difference between the two groups was striking. The rats who hadn’t been licked and groomed much as pups spent, on average, fewer than five seconds of their five minutes daring to explore the inner part of the open field; the rats who had been licked and groomed a lot as pups spent, on average, thirty-five seconds in the inner field—seven times as long. In the ten-minute food test, high-LG rats began eating, on average, after just four tentative minutes, and they ate for more than two minutes in total. The low-LG rats took, on average, more than nine minutes to start eating, and once they did, they ate for only a few seconds.
The researchers ran test after test, and on each one, the high-LG offspring excelled: They were better at mazes. They were more social. They were more curious. They were less aggressive. They had more self-control. They were healthier. They lived longer. Meaney and his researchers were astounded. What seemed like a tiny variation in early mothering style, so small that decades of researchers hadn’t noticed it, created huge behavioral differences in mature rats, months after the licking and grooming had taken place. And the effect wasn’t just behavioral; it was biological too. When Meaney’s researchers examined the brains of the adult rats, they found significant differences in the stress-response systems of the high-LG and low-LG rats, including big variations in the size and shape and complexity of the parts of the brain that regulated stress.
Meaney wondered if a dam’s licking-and-grooming frequency was just a proxy for some genetic trait that was passed on from mother to child. Maybe nervous dams produced temperamentally nervous pups, and those dams also coincidentally happened to be less inclined to lick and groom. To test that hypothesis, Meaney and his researchers did a number of cross-fostering experiments, in which they removed pups at birth from a high-LG dam and put them in the litter of a low-LG dam, and vice versa, in all kinds of combinations. Whatever permutation they chose, though, however they performed the experiment, they found the same thing: what mattered was not the licking-and-grooming habits of the biological mother; it was the licking-and-grooming habits of the
10. Attachment
