About half the world’s population live in cities, and that will be two-thirds by 2050. But modern cities are not like any environment we’ve evolved to live in, so we need to ask: Are modern cities clashing with the ancient design of our bodies and our minds? Are cities making us sad?
Well, here’s three ways that they can:
Cities are very good at cramming a lot of people into tiny space. Where you have a lot of people, you have a lot of social stress. What’s social stress? Imagine trying to do an eighth-grade math exam under timed conditions while someone shouts at you. That’s social stress. Pop yourself into an MRI scanner and you’ve got the exact experiment that Lederbogen and colleagues did some years ago to see if there was a difference between city dwellers and country folk in their response to social stress. Spoiler alert: There is. The amygdala is more activiated in city people than in country people. The amygdala -- which comes up a lot in these videos -- is a subcortical brain structure which controls, among other things, anxiety and depression. So it might be that the increased amygdala activity makes city dwellers more prone to depression -- and that is exactly what an analysis of the medical literature had found the year before. So, city-specific depression could well be caused by increased social stress, operating through the amygdala, from the sheer number of nearby people.
Where you have lots of people, you have lots of pollution, and that pollution can come in many forms: chemicals in the air from car exhaust, bright lights from street lamps, and the endless roar of combustion engines day and night. Both chemical and light pollution have been linked to human stress and suffering.
But on top of all of this, cities are very complicated. Unlike natural environments, which are interesting without demanding attention, cites are dangerous, gaudy and exciting, which also makes them exhausting for our attention. At some point fun always becomes tiring. The flip side to that is if we can’t handle the daily hustle, we might feel a lack of control. If we don’t feel we can control our lives, then we may suffer from learned helplessness -- which is a model of depression.
So. Cities are busy, polluted and complicated and any one of these can make us feel unhappy. But there's a reason so many people live in the city. Employment, healthcare, education, culture -- those are often better in the city. So is there some that way we can make our cites more joyful places to live? Here’s a few of suggestions from the academic literature:
- Produce less exhaust. Inhaling poisonous fumes will make you sad. All the studies seem to agree on that.
- Go for a walk in the countryside, or more specifically, go for a 90-minute walk in the greenspace outside Stanford University, California, in the year 2014. One study found that this decreased the amount of brain activity in the brain area responsible with ruminative thinking, which is often active during depression. Or, if you live in Japan, you could try some ‘Shinrin Yoku’ -- that’s forest bathing. It’s basically the same thing, but the supporting evidence is a lot less clear.
- Bring the green to the city. Urban green spaces have been shown to improve social cohesion and decrease stress (as shown by the stress hormone cortisol). In fact, in the Robert Taylor Housing estate in Chicago when they planted trees, they also improved neighborhood ties and made people feel safer.
Our cities are humanity’s future home. We should probably try to make them nice places to live.