Living in a violent neighborhood affects children’s brain development

Study (PDF): Exposure to Community Violence as a Mechanism Linking Neighborhood Disadvantage to Amygdala Reactivity and the Protective Role of Parental Nurturance

Living in neighborhoods with high levels of violence can affect children’s development by changing the way that a part of the brain detects and responds to potential threats, which could lead to poorer mental health and other negative outcomes.

But these findings from a new University of Michigan study, published in Developmental Psychology, also indicate that nurturing parents can help protect kids against these detrimental effects.

Decades of research have shown that growing up in neighborhoods with concentrated disadvantages can predict negative academic, behavioral and mental health outcomes in children and teens. Recent research is beginning to show that one way it does that is by impacting the developing brain, said study co-author Luke Hyde , U-M professor of psychology.

"However, less is known about how neighborhood disadvantage ’gets under the skin’ to impact brain development,- he said.

Hyde and colleagues hypothesized that one way might be through the amygdala, the hub of the brain’s stress response system that’s involved in socioemotional functioning, threat processing and fear learning.

The amygdala is sensitive to facial expressions. Previous research has found that children who have been abused or neglected by family members, for example, show increased reactivity in the amygdala when looking at faces with negative, fearful or neutral expressions.

To study whether exposure to neighborhood violence might also affect youth’s amygdala reactivity, the researchers analyzed data from 708 children and teens ages 7 to 19, recruited from 354 families enrolled in the Michigan Twins Neurogenetic Study.

Most were from neighborhoods with above-average levels of poverty and disadvantage, as measured by the U.S. Census Bureau. Fifty-four percent of the participants were boys, 78.5% were white, 13% were Black and 8% were other races and ethnicities. The participants lived in a mix of rural, suburban and urban areas in and around Lansing, Michigan.

Participants completed surveys that asked about their exposure to community violence, their relationship with their parents, and their parents’ parenting style. They also took part in an experiment in which their brains were scanned by functional MRI while they looked at faces that were angry, fearful, happy or neutral.

Overall, the researchers found that participants who lived in more disadvantaged neighborhoods reported more exposure to community violence. And participants who reported more exposure to community violence showed higher levels of amygdala reactivity to fearful and angry faces. The results held even when controlling for an individual family’s income, parental education and other socioeconomic factors as well as forms of violence exposure in the home.

"This makes sense as it’s adaptive for adolescents to be more in tune to threats when living in a more dangerous neighborhood,- Hyde said.

However, the researchers also found that nurturing parents seemed to be able to break the link between community violence and amygdala reactivity.

"Children with more nurturing and involved parents were not as likely to be exposed to community violence, and for those who were exposed, having a more nurturing parent diminished the impact of violence exposure on the brain,- said Gabriela Suarez , a U-M graduate student in developmental psychology and the study’s lead author.

"These findings highlight how nurturing and involved parents are helping to support their children’s success, even in potentially harsh environments, and offer clues as to why some youth are resilient even when facing adversity.-

The study highlights the need for structural solutions to protect children from the negative impact of exposure to community violence. It also points to how strong, positive parents can promote resilience among children and teens exposed to adversity, the researchers said.

"Parents may be an important buffer against these broader structural inequalities, and thus working with parents may be one way to help protect children-while we also work on policies to reduce the concentration of disadvantage in neighborhoods and the risk for exposure to violence in the community,- said co-author Alex Burt , professor of psychology at Michigan State University.

Other study co-authors are Kelly Klump, MSU professor of psychology, and Arianna Gard, a doctoral candidate at the University of Maryland.