Neighborhoods - social immune systems

Night skyline of Calgary - city of neighborhoods, residential towers and site of the 2026 CanAm ICA CPTED Conference

by Gregory Saville

I’ve been diving into some exciting reading starting with a disturbing sci-fi called Scythe. It’s the story of a future where AI has helped humanity conquer disease, aging, and accidental death and now governs society with near-perfect efficiency. Scythe reads like the smooth winter ice on a northern lake that seems safe, right up to the moment it begins to crack beneath you. 

I’m also re-reading two non-fiction books. They are more challenging, perhaps because they are real and like life, contain possibilities for multiple futures. 

The first book, Paul Hawken’s 2007 Blessed Unrest, is a sweeping account of the vast, decentralized movement of environmental, social justice, and community organizations quietly reshaping the moral ecology of the world in recent decades. It is a story in which much has already come to pass. 

His book reads as a cultural argument rather than an empirical one. Hawken does not offer crime statistics or econometric models. He is describing something more organic: the emergence of civil society as a kind of adaptive immune system responding to social harm. Steven Pinker has convincingly posed a similar argument over a longer historical arc in Enlightenment Now. For practical examples, check out our blogs on Denver's adaptive reuse community marketplaces and Third Places for the homeless in Madison.

East Village riverwalk views in Calgary - location of one of the Jane's Walk Tours during the 2026 CPTED conference - Street activation means incorporating nature

 

THE GREAT CRIME DECLINE CONTINUES

Are there data to support this urban adaptive immune system? 

The Great Crime Decline started in the 1990s and accelerated from 2007 and 2017. In the United States, FBI Uniform Crime Reports document declines in the crime rates, including statistics that show the national violent crime rate declined 18.9 percent over a decade. It is one of the steepest and most sustained drops in modern U.S. history. 

Interestingly, over that same period, the U.S. Bureau of Labor Statistics reports that the number of nonprofit organizations grew by roughly 29 percent, while employment within those organizations increased by about 18 percent. Growth in the for-profit sector over the same period was far more modest.

CORRELATION ≠ CAUSATION...SYMMETRY > 0

It’s important to note these correlations do not prove Hawken’s thesis. Then again few social theories are ever conclusively proven and, taken on whole, there is no denying the empirical weight suggested by these trends. Further, society might not look very civil in today’s news in this country, but this civilizing pattern happened over decades, not within the past year. 

Nonprofits and Third Places in civil society may not directly cause crime drops since neighborhoods are ecosystems that evolve together across the city in complex ways. But it is worth restating a powerful, and obvious, hypotheses – improvements in civic capacity have direct impact on livability and for crime. This hypothesis has been shown true in different studies over the years, for example: Community and the Crime Decline: The Causal Effect of Local Nonprofits on Violent Crime.

Comeback Cities by Paul S. Grogan and Tony Proscio 

HOW DOES IT WORK?

The second book, Comeback Cities: A Blueprint for Urban Neighborhood Revival, answers how this works. Paul Grogan and Tony Proscio examine how American cities began recovering in the 1990s after decades of disinvestment. Their conclusion? Urban revival did not come from top-down policy or market forces alone! It came from the slow reconstruction of neighborhood institutions, community development corporations, and housing nonprofits. Street activation was the key. That is a very similar long-term strategy upon which SafeGrowth works to rebuild trust and local ownership.

Criminologists Tarah Hodgkinson and Martin Andresen reinforce this very point in their study Preventing Crime at Places by examining the limits of place-based prevention approaches that focus narrowly on opportunity reduction rather than underlying motives.

“By building cohesive networks of capable community partners, integrated strategies can improve the overall well-being of the community through local governance systems.”

Where do we look for places of activation? A few include libraries, cultural spaces, shared work hubs, neighborhood cafés, arts centers, and informal gathering sites. These places are not simply amenities. They function as social infrastructure, creating routine contact and informal guardianship. Our blog on the Denver Art Society as a Third Place, shows how they improve street life through problem-solving.

 

Public art in Calgary. Great places need cultural statements
- proof that cities, like people, benefit from a little headspace

THE STORY WE KEEP MISSING 

As urban chaos captures our attention across the country, another story has been quietly unfolding. We examine this story in depth in Hope Rises, our forthcoming book.

This story sits at the core of our livability thesis. Rather than treating crime as a technical failure to be corrected by AI, we need to focus on strengthening the everyday environments where people meet, live and play. Environments like ecologically designed village-style housing and urban green spaces/parks.  

When cities invest in social infrastructure, whether through housing organizations or grassroots nonprofits, they reinforce the conditions that make violence less likely to take hold. When cities organize neighborhoods with interlinked safety plans and opportunities for resident-led problem-solving, they create opportunities to expand social resilience.

The book Scythe imagines a dystopia that is not inevitable. We believe public safety is ecological, and livability is one of its primary engines.

--------

POSTSCRIPT Feb 12

In the week following this blog, Henry Grabar published an article in The Atlantic  about recent crime declines in cities across the country. He compares the massive public-sector investments that align with these declines. Grabar says the latest steep crime declines quite probably emerge from federal pandemic-related stimulus funding. That is an interesting thesis since, from the social immunity thesis in this blog, it confirms that recent crime declines are an acceleration of the multi-year crime decline trajectory existing for decades. And those declines also may be driven by neighborhood social capacity building. In short, capacity-building and public investment provides the fuel to power already existing civic ecosystems in cities across the country. The takeaway? Careful and targeted social invest works! 

Social immune systems offer a future we can no longer ignore.