Thursday, March 21, 2013

Poverty and Stress: The Ability of Children to Learn

Those who study the data on the academic attainment of our children must inevitably conclude that poverty is a factor in determining whether an individual child is likely to be successful. Given that knowledge, what does one do about it? How can one provide better educational outcomes for children who live in poverty? Most often the response is to provide more of what seems to be successful with advantaged children, but the results have been disappointing. Could there be an association with poverty that is deeper, more fundamental, and more complex than we have imagined? That is the thesis Paul Tough presents in his book How Children Succeed: Grit, Curiosity, and the Hidden Power of Character.

Tough’s story begins with a remarkable study performed by Kaiser Permanente in the 1990s. This health maintenance organization began surveying members with a focus on gathering information on traumatic childhood experiences. The information collected could then be correlated with the organization’s medical records for the survey participants. The results were tabulated for a large group that was representative of the middle class rather than having any particular association with issues of poverty. The results were published in a paper written by Vincent Felitti and Robert Anda under the title The Relationship of Adverse Childhood Experiences to Adult Health: Turning Gold into Lead. This work is commonly referred to as the ACE study with the acronym representing "adverse childhood experiences."

The first revelation from the study was the frequency of childhood trauma.

"More than a quarter of the patients said they had grown up in a household with an alcoholic or a drug user; about the same fraction had been beaten as children. When the doctors used the data to assign each patient an ACE score, giving them one point for each category of trauma they had experienced, they found that two-thirds of the patients had experienced at least one ACE, and one in eight had an ACE score of 4 or more."

When correlations were made between the results of the survey and the health outcomes of the patients, startling results were obtained.

"The correlations between adverse childhood experiences and negative adult outcomes were so powerful that they ‘stunned us,’ Anda later wrote. What’s more, those correlations seemed to follow a surprisingly linear dose-response model: the higher the ACE score, the worse the outcome on almost every measure from addictive behavior to chronic disease."

We are used to thinking that social and emotional problems can lead to unhealthy lifestyles that can cause enhanced probability for disease, but there is more going on than that.

"When they looked at patients with high ACE scores (7 or more) who didn’t smoke. didn’t drink to excess, and weren’t overweight, they found that their risk of ischemic heart disease (the single most common cause of death in the United States) was still 360 percent higher than those with an ACE score of 0."

The conclusion that was reached by the authors and subsequent researchers was:

"The adversity these patients had experienced in childhood was making them sick through a pathway that had nothing to do with behavior."

Researchers have since concluded that the villain in this story, the one that causes physical and mental damage to bodies, is the response to stress that evolution has developed in our bodies. For most of our evolution stress was associated with life or death situations. The appropriate response in that case is to max out all possible reactions to a threatening situation. Unfortunately for modern humans, stress has become frequent, often long and drawn out, and sometimes chronic. A response system designed to be life saving, can be life threatening if over used.

"Our bodies regulate stress using a system called the HPA axis. HPA stands for ‘hypothalamic-pituitary-adrenal’....when a potential danger appears, the first line of defense is the hypothalamus, the region of the brain that controls unconscious biological processes....The hypothalamus emits a chemical that triggers receptors in the pituitary gland; the pituitary releases signaling hormones that stimulate the adrenal glands; and the adrenal glands then send out stress hormones called glucocorticoids that switch on a host of specific defense responses."

Some of these responses are apparent to us such as higher blood pressure and a faster heart rate. Others are less observable to us:

"....neurotransmitters activate, glucose levels rise, the cardiovascular system sends blood to the muscles, and inflammatory proteins surge through the bloodstream."

The burden this stress response places on the body is referred to as alostatic load. Too high an alostatic load:

"....especially in infancy and childhood, produces all kinds of serious and long-lasting negative effects—physical, psychological, and neurological."

How does this specifically relate to poverty and learning? Being poor is not detrimental in itself, but poverty makes it likely that children will experience more frequent and more intense stressful situations. Physical, sexual, and emotional abuse become more likely. Physical security and emotional security are often at risk. Not knowing where your next meal will come from can definitely be stressful.

Those who study the physiology of stress have learned that the prefrontal cortex is the part of the brain most susceptible to damage in children subjected to abnormal amounts of stress.

"The part of the brain most affected by early stress is the prefrontal cortex, which is critical in self-regulatory activities of all kinds, both emotional and cognitive. As a result, children who grow up in stressful environments generally find it harder to concentrate, harder to sit still, harder to rebound from disappointments, and harder to follow directions. And that has a direct effect on their performance in school."

Tough refers to these "self-regulatory activities" controlled by the prefrontal cortex as "executive functions." He does not view the fact that these processes have been compromised in many poor children as the end of the story.

"The reason that researchers who care about the gap between the rich and the poor are so excited about executive functions is that these skills are not only highly predictive of success; they are also quite malleable, much more so than other cognitive skills. The prefrontal cortex is more responsive to intervention than other parts of the brain, and it stays flexible well into adolescence and early adulthood. So if we can improve a child’s environment in the specific ways that lead to better executive functioning, we can increase his prospects for success in a particularly efficient way."

Tough provides examples where disadvantaged children with poor early educational experiences were converted into productive students with potentially bright futures. He emphasizes that the rehabilitation of these children’s educations requires not just better approaches to subjects like math and reading comprehension, but it also requires a conscious effort to help students attain greater control of these executive functions.

What matters most in a child’s development....is not how much information we can stuff into her brain in the first few years. What matters, instead, is whether we are able to help her develop a very different set of qualities, a list that includes persistence, self-control, curiosity, conscientiousness, grit, and self-confidence. Economists refer to these as noncognitive skills, psychologists call them personality traits, and the rest of us sometimes think of them as character."

Further discussion of Tough’s book and the subject of enhancing the performance of disadvantaged children can be found in Education: Success, Failure, and Character.

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