We know that when it comes to your health, your zip code matters more than your genetic code. Zip code is shorthand for neighborhoods and it is there that chronic stress-inducing conditions shape the present and future of the residents. For instance, in Alameda County, an African-American child from East Oakland can expect to live 15 fewer years than a White child from the Oakland Hills, only several miles away. We know that this difference can’t be explained by access to health care or genetics, which are important, but a small part of the story. What really matters are the “social determinants of health” or the neighborhood conditions in which people are born and grow-up.

When it comes to neighborhood conditions, perhaps the most important factor are the social connections —or cohesion—in the neighborhoods. In places where connections are strong, there is more investment in the neighborhood—in businesses, infrastructure, schools, all of which are important factors for health. Not all poor communities are the same.

The California Endowment’s own research shows that there are a number of neighborhoods in California where, despite a 50% poverty rate, life expectancy is quite high. These neighborhoods are statistical outliers. They defy the general correlation between poverty and shortened lifespans. What is their secret? Why do these communities seem to be so resilient in the face of poverty and adversity? This is a question that public health and social science researchers have been studying for some time. Eric Klinenberg’s research into a Chicago heat wave shed some light on this question.

The 1995 Chicago heat wave killed seven hundred and thirty-nine people. Analysis revealed expected patterns—heat-wave related deaths closely followed segregated neighborhoods and poverty—but it also surfaced unexpected conditions that protected the lives of vulnerable Chicago residents. Eight of the ten community areas with the highest death rates were hyper-segregated African-American neighborhoods with high concentrations of poverty and violent crime. Three of the ten neighborhoods with the lowest heat wave death rates bucked the pattern, as they were also hyper-segregated African-American neighborhoods with high concentrations of poverty and violent crime.

The major difference between the neighborhoods with similar demographics but vastly different death rates was the strength of the social ties, and those ties were also related to how much investment that neighborhood had seen in the prior decades. As a 2013 article in the New Yorker explains:

The key difference between neighborhoods… turned out to be the sidewalks, stores, restaurants, and community organizations that bring people into contact with friends and neighbors. The people of Englewood were vulnerable not just because they were black and poor but also because their community had been abandoned.

Between 1960 and 1990, Englewood lost fifty per cent of its residents and most of its commercial outlets, as well as its social cohesion. “We used to be much closer, more tight-knit,” says Hal Baskin, who has lived in Englewood for fifty-two years and currently leads a campaign against neighborhood violence. “Now we don’t know who lives across the street or around the corner. And old folks are apprehensive about leaving their homes.”

Auburn Gresham, by contrast, experienced no population loss during that period. In 1995, residents walked to diners and grocery stores. They knew their neighbors. They participated in block clubs and church groups. “During the heat wave, we were doing wellness checks, asking neighbors to knock on each other’s doors,” Betty Swanson, who has lived in Auburn Gresham for nearly fifty years, says. “The presidents of our block clubs usually know who’s alone, who’s aging, who’s sick. It’s what we always do when it’s very hot or very cold here.”

Building Healthy Communities is focused on place because it is the environments in which we grow up, are educated, and work that determine our health outcomes. We are also focused on place because community is where individuals often find deep purpose and a sense of belonging. Strong communities are characterized by strong and dense relationship networks. These communities are resilient and can help protect individuals from adversity. So while adverse community conditions are the product of policy and politics, building power in place is key to creating strong and resilient communities that can protect residents and drive policy change today and beyond.