When a child flinches at a loud noise or freezes up near a stranger on the street, every parent knows what’s going on. Mostly, that’s just being careful as a child. But what happens when those times don’t just happen once in a while? What happens when the sound of sirens, loud voices, or worse is played over and over again in a child’s head? That question has been bothering researchers for years. Scientists are now beginning to understand what many families who live in areas with a lot of violence have known for a long time.
A study in the journal Developmental Psychology looked at information from 708 kids and teens from families who were part of the Michigan Twins Neurogenetic Study. The kids and teens were between the ages of 7 and 19. In most of the places they lived, there were higher than average levels of poverty and disadvantage. Researchers used a functional MRI to scan their brains while showing them faces that showed how angry, scared, happy, or neutral they were. It was shocking what they found, but maybe not too much of a surprise.
The amygdala is the part of the brain that detects threats and controls fear. Children who said they had been exposed to more community violence had significantly higher reactivity in this area. This part of the brain does more than just deal with danger. It also affects how people see the world and how long they feel threatened. This part of the brain is especially sensitive during childhood and adolescence, which is why things that happen there tend to stay with you.
What was so interesting about the results was that they couldn’t be explained by household income or parenting education alone. Even when family poverty and other types of stress at home were taken into account, the violence in the neighborhood still left a mark on the brain. The community setting, separate from home, was doing something measurable to help minds grow. That’s a pretty big find. It changes the focus of the conversation from the specifics of each family’s situation to the bigger picture of the world children are born into.
Some earlier studies, like one from Cornell University in the middle of the 2000s, made this picture more complicated in interesting ways. That study discovered that acting aggressively in a violent neighborhood seemed to protect teenage boys from depression, which may seem counterintuitive. The researchers thought it might be an adaptive response, or a way to keep a sense of control when things around you feel out of your control. That’s a scary kind of resilience—the kind that keeps someone safe in the short term but might limit their choices in the long term. Not all changes are good for you.
All of the new research does have one more hopeful thread, though. A study from the University of Michigan found that caring parents seemed to really act as a buffer. When kids had parents who were loving and involved, they were less likely to be exposed to violence in the first place. And when they were, the effects on their brains were less severe. It’s possible that when a child feels emotionally safe at home, their nervous system learns that the world is not completely unpredictable, even though there is evidence to the contrary. It looks like that kind of comfort can go a long way.
All of this doesn’t mean that each parent should have to fix structural inequality. That’s what the researchers said, so it makes sense to believe them. There are programs that can help parents. So can neighborhoods that are really safe. The research doesn’t say which is better; it suggests that both are important, but in different ways and at different times in a child’s growth.
A simple, unsettling thought stays with me after reading this research: the place where a child grows up physically affects their biology. Not in a figurative way. In fact. The streets, the noises, and the constant low-level tension of a dangerous block all change the structure of the brain in ways that last. That sounds like something you should sit down with.
