A Bright Idea on Crime

It’s a basic part of being human: we’re scared of the dark. And sure, most of us act like it’s something that only applies to kids, but think about where adults go to get their thrills.

Horror movies? In the dark.

Haunted houses? In the dark.

Shame-eating an entire pack of Oreos? Yeah, you’re probably doing that in the dark too.

But here’s the thing: our fear of the dark is, in some ways, deeply rational. In fact, in cities throughout America, being scared of the dark ... could save your life.

Why are humans so creeped out by darkness? Scientists conjecture that it’s an evolutionary response to a pretty basic fact: before modern technology, we weren’t exactly at the top of the food chain. If our ancestors ventured out onto the African plains after dark ... they might not make it back.

In fact, a 2011 study in Tanzania showed that the vast majority of lion attacks on humans occur at night — and disproportionately on the darkest nights of the month.ⁱ Because when you can’t see is when you’re at your most vulnerable.

And what was true in the wild tens of thousands of years ago is equally true when it comes to life in major cities today: darkness tends to be followed by disorder.

In cities across America, public spaces are too often unlit, either because local officials aren’t keeping up on maintenance, criminals are shooting out the lights, or both. And chaos too often follows.

In 2012, for instance, it was reported that around 40 percent of the streetlights in Detroit were broken.ⁱⁱ That same year, Forbes magazine ranked Detroit as America’s most dangerous city. ⁱⁱⁱ Some experts suspect that’s not a coincidence.

In 2016, researchers from the University of Chicago’s crime lab set out to see just how much of a difference lighting could make for public safety. A team in New York City took 80 public housing complexes with high crime rates and randomly separated them into two groups of 40. Half of them were given bright nighttime lighting. Half of them weren’t.

The result: in places that got new lights, index crimes (offenses like murder, robbery, assault, and car theft) dropped by 36 percent within a two-block radius. If you focused just on the area where the lights were actually installed, they were down 60 percent.^iv

Just this one simple change had the same effect as increasing police presence by 10 percent.

Now, you might think this sounds impractical. After all, it’s not like we can cover every inch of the country in light. But here’s the good news: we don’t have to. Because one of the keys to understanding public safety in the United States is this: serious crime is overwhelmingly concentrated in a small handful of neighborhoods.

Just two percent of counties in America, for instance, have 51 percent of the country’s murders. ^v

A 2004 study in Seattle found that 50 percent of the city’s crime came from just five percent of its street segments.^vi Brightening up places like those could literally be a life-saving proposition for the people living in and around those neighborhoods — and by the way, those people are overwhelmingly underprivileged. After all, if the lights go out in a nice suburb, you better believe they’ll be fixed within a few days.

More lights can’t solve everything, of course. To keep our neighborhoods safe, we’ll still need well-trained cops walking the beat and citizens monitoring their communities through programs like the Neighborhood Watch.

Combatting violence and disorder is hard work. But that just makes it all the more important to take advantage of the rare situations where reducing crime is as simple as flipping a switch.