The possible long-term impacts of high levels of stress in early life are emerging in large-scale correlational studies, and the biological mechanisms that may be at work are being studied in animal models such as mice, rats and macaque monkeys.
…Cameron has studied how the stress of growing up in unsettled, sometimes violent circumstances affects the development of young brains and increases the risk for destructive behavior and long-term health problems in adult life. Cameron and Earls emphasized that early intervention, both at the community and the personal levels, can make an important difference in a child’s life prospects.
…Childhood experiences, both good and bad, can affect the developing architecture of the brain. …Experiences and environment also determine whether neural circuits involved with motor skills, behavior control, memory and other functions form robustly. Experiences also can influence gene expression in the developing brain by affecting the production of proteins that bind to DNA in the neurons, Cameron said. Scientists are just starting to understand such “epigenetic” factors in brain development.
When the body’s response to stress — the rush of adrenaline, the increase in heart rate, the elevation of certain hormone levels — is constantly active, Cameron said, the result is “toxic stress” that can reduce the number of neural connections in the cognitive areas of the brain at a time when they should be proliferating.
…Communities were being described by race and class, Earls said, but his team wanted to know how they functioned: Are children exposed to good supervision? Would neighbors intervene if they saw children skipping school or spray-painting graffiti on a wall? Or showing disrespect to an adult?
The most important influence on a neighborhood’s crime rate, the researchers found, was the neighbors’ sense of “agency” or willingness to intervene on behalf of the common good. Based on detailed interviews with 8,782 residents representing each of the 343 neighborhoods in the study, the researchers were able to assign a “collective efficacy” value for each neighborhood. That combined measure of informal social control, cohesion and trust proved to be a robust predictor of lower violence rates in a neighborhood.
…”We found that collective efficacy was, indeed, operating as a protective factor,” he said.
The researchers also found that the benefits of collective efficacy go beyond easing violence. It also seems to be associated with more use of parks and recreational spaces in neighborhoods, initiation of sexual activity at later ages among youths, and even less obesity and fewer admissions to hospitals for asthma attacks. While such findings are based on correlations rather than cause-and-effect, the study does suggest that the general welfare of a neighborhood improves when people have a greater sense of social control.
…”When given an opportunity which is structured and self-guided and responsible and dignifies and respects children, there is a tremendous opportunity to curb the bad influences and produce more positive outcomes,” [Earls said.]