Corrected: This story includes corrected titles for Jack Shonkoff and Pat Levitt.
The stress of a spelling bee or a challenging science project can enhance a student鈥檚 focus and promote learning. But the stress of a dysfunctional or unstable home life can poison a child鈥檚 cognitive ability for a lifetime, according to new research.
While educators and psychologists have said for decades that the effects of poverty interfere with students鈥� academic achievement, new evidence from cognitive and neuroscience is showing exactly how adversity in childhood damages students鈥� long-term learning and health.
Those studies show that stress forms the link between childhood adversity and poor academic achievement, but that not all adversity鈥攐r all stress鈥攊s bad for students.
鈥淐hildren from their earliest life need to learn how to manage adversity,鈥� such as dealing with the first day of school, said Dr. Jack P. Shonkoff, the director of Harvard University鈥檚 Center on the Developing Child, in Cambridge, Mass.
As part of the Adverse Childhood Experiences Study, more than 17,400 adults in San Diego County were assigned scores based on the number of risk factors each experienced as a child, including abuse or neglect, or growing up in homes with domestic violence, drug abuse or mental illness, or absent parents. Researchers found that people with higher ACE scores were more likely to experience underage sex or pregnancy, among other health risks.
SOURCE: Adverse Child Experiences Study
Research from Dr. Shonkoff鈥檚 center and from other experts finds that positive stress鈥攖he kind that comes from telling a toddler he can鈥檛 have a cookie or a teenager that she鈥檚 about to take a pop quiz鈥攃auses a brief rise in heart rate and stress hormones. A jolt can focus a student鈥檚 attention and is generally considered healthy.
Similarly, a child can tolerate stress that is severe but may be relatively short-term鈥攆rom the death of a loved one, for example鈥攁s long as he or she has support.
鈥淎dults help children develop strategies to help cope with these stressors,鈥� Dr. Shonkoff said. 鈥淲hether it鈥檚 reading or managing stress, adults provide the scaffolding for children to build those skills themselves.鈥�
鈥楾oxic鈥� Recipe
By contrast, so-called 鈥渢oxic stress鈥� is severe, sustained, and not buffered by supportive relationships.
The same brain flexibility, called plasticity, that makes children open to learning in their early years also makes them particularly vulnerable to damage from the toxic stressors that often accompany poverty: high mobility and homelessness; hunger and food instability; parents who are in jail or absent; domestic violence; drug abuse; and other problems, according to Pat Levitt, a developmental neuroscientist at the University of Southern California and the director of the neuroscience graduate program at the Keck School of Medicine in Los Angeles. Both Mr. Levitt and Dr. Shonkoff are part of the National Scientific Council on the Developing Child, which is studying the effects of environment on children鈥檚 health and cognitive development.
The exponential brain growth of infancy and early childhood also makes children more vulnerable to chronic stress during those years than at other developmental periods, according to the National Scientific Council on the Developing Child, an interdisciplinary group of neuroscientists, psychologists, economists, and education researchers. In a series of easy-to-understand, peer-reviewed videos, the group explains how early cognitive connections form鈥攁nd break down.
Experiences Build Brain Architecture
Serve & Return Interaction Shapes Brain Circuitry
Toxic Stress Derails Healthy Development
SOURCE: Center on the Developing Child, Harvard University
Good experiences, like nurturing parents and rich early-child-care environments, help build and reinforce neural connections in areas such as language development and self-control, while adversity weakens those connections.
Over time, the connections, good or bad, stabilize, 鈥渁nd you can鈥檛 go back and rewire; you have to adapt,鈥� Dr. Shonkoff said. 鈥淚f you鈥檝e built on strong foundations, that鈥檚 good, and if you have weak foundations, the brain has to work harder, and it costs more to the brain and society.鈥�
For example, a study in the October issue of the peer-reviewed journal Child Development found that out of more than 26,000 students in the Minneapolis public schools, those who moved more than three times a year had significantly lower mathematics achievement and academic growth than students with more stable homes.
In a separate study, Richard P. Barth, the dean and a professor of social work at the University of Maryland College Park, found children with six or more adverse experiences before age 3 were overwhelmingly likely to be identified as needing special education for developmental delay.
Self-Control or Trust?
Moreover, a child鈥檚 ability to delay gratification and control him- or herself鈥攐ften seen as a personality trait critical for academic success鈥攃an be hugely dependent on the child鈥檚 sense of stability in the environment and trust in surrounding adults.
In a twist on the classic Stanford University 鈥渕arshmallow experiment,鈥� in which young children鈥檚 ability to resist eating a marshmallow was tested to show their self-control, researchers led by Celeste Kidd, a professor of brain and cognitive sciences at the University of Rochester in New York recently found children who trusted the word of the adult tester and felt their environment was more stable waited four times as long for a treat as those who felt more insecure.
The effects of early stress can linger for decades and go well beyond learning difficulties.
鈥淲hat happens in childhood, like a child鈥檚 footprint in wet cement, leaves its mark forever,鈥� said Dr. Vincent J. Felitti, the director of the Adverse Childhood Experiences Study at the health-care provider Kaiser Permanente鈥檚 department of preventive medicine in San Diego.
Known as the ACE study and done in collaboration with Dr. Robert F. Anda at the federal Centers for Disease Control and Prevention in Atlanta, the project analyzed longitudinal data on more than 17,400 middle-class adults in the Kaiser Permanente system.
Participants reported whether, as children, they had experienced repeated physical, sexual, or severe emotional abuse, and whether they had grown up with any of five types of 鈥渉ousehold dysfunction": a family member in prison; domestic violence; an alcoholic or drug abuser in the home; someone in the home who was depressed, mentally ill, or suicidal; or loss of at least one biological parent during childhood for any reason.
Adversity, Decades Later
As it turned out, more than half the adults had had at least one type of severe abuse or home dysfunction in childhood, and one in 16 had experienced four or more. The number of traumatic childhood experiences, Dr. Felitti found, was directly proportional to a person鈥檚 risk of a wide variety of major medical and social problems, from teenage pregnancy and drug abuse to adult heart disease and hepatitis.
鈥淭hese results are almost unique in their magnitude,鈥� Dr. Felitti said. A boy with six indicators of abuse and home dysfunction was 4,600 percent more likely than a boy with no risk factors to become an intravenous-drug user, according to the study.
Such findings mean that teachers and doctors are left trying to fix late symptoms, like poor reading skills or boredom in school, rather than underlying issues that occur much earlier in life.
鈥淭he science [on the effects of poverty and stress] has exploded in the last 25 years, but the policy on the delivery of child care has stalled, without anything close to similar progress,鈥� Dr. Shonkoff said.
While federal and state education programs typically focus on academic remediation and nutrition for disadvantaged students, 鈥渇or some kids, no matter how well you do that, it鈥檚 not enough, because the amount of adversity in their lives overwhelms,鈥� he said.
鈥淚t鈥檚 asking too much,鈥� Dr. Shonkoff said, 鈥渢o require parent education and an enriched preschool program to counteract the effects of the level of adversity in some kids鈥� lives that is whipping up their stress-response systems.鈥�
Researchers, including Mr. Levitt of USC and Dr. Felitti, are starting to explore new interventions, both medical and cognitive, that might protect children鈥檚 developing brains from damage caused by stress and improve their ability to cope.
So far, there are no classroom-ready techniques beyond developing supportive relationships between teachers and parents and their children, Mr. Levitt said. 鈥淗elping people after the fact is really nibbling at the edges of the problems,鈥� Dr. Felitti said during a presentation on the research at the Society for Neuroscience conference in New Orleans last month. 鈥淲e need a polio vaccine, as opposed to buying bigger and better iron lungs.鈥�
鈥淪tress is not something you get a lot of sympathy for,鈥� Dr. Shonkoff said in a separate interview at the Society for Research in 91制片厂视频al Effectiveness meeting in Washington. 鈥淭his is a culture that says suck it up and get over it.鈥�
But in reality, Dr. Felitti concluded, 鈥渢he [ACE] study makes it clear that time does not heal some of the adverse experiences we found so common. ... One does not 鈥榡ust get over鈥� some things, not even 50 years later.鈥�
