Here’s this week’s Media Mix, which is about the media’s fascination with the burgeoning ranks of the senile. Aside from the obvious economic ramifications, which the column goes into, there is an underlying question of whether or not dementia is more prevalent from an organic standpoint. The basic assumption is that it will become a problem due to sheer numbers, that the very size of the boomer cohort is what it’s all about. But a sidelight of senility coverage over the years is what people can do to put off cognitive dysfunction. Usually, the answer is unoriginal: keep yourself healthy by eating right and exercising. Secondarily, one should remain mentally active and stimulated–take up a foreign language or keep a diary; make your hands busy by knitting or gardening. Japanese TV shows revel in the centenarian who is still cognitively sharp and gets around. In many cases these people are women who still work in the fields every day. It’s a convincing portrait of vitality and feels like common sense: If you have a reason to live, a reason to look forward to getting up every morning (as opposed to simply a reason to get up), then your body and mind will accommodate that desire by staying well longer.

These considerations have mostly been ignored in the recent coverage, and, of course, they are integral to the discussion. But there is another assumption at work that perhaps goes without saying. All the individual cases covered in these articles and broadcasts were of people living in urban environments. It’s another truism that feels tired, but as Johnny said so memorably in Mike Leigh’s Naked, after somebody says that a cliche always has some truth in it: “That’s a cliche, too.” As developed societies, and not just Japan’s, have moved from the country to the city, people become more isolated, which sounds counterintuitive but really isn’t. Rural life, with its closer proximity to the elements and uncertainty, requires greater community cohesion for people to survive, whereas in cities the infrastructure keeps uncertainty at bay. The circumstance that almost all of the senile people portrayed in the media have in common is isolation–even when they’re married and their partner is taking care of them. Without a community that nurtures real emotional responses–and that includes anger, fear, and any other negative feeling you can think of–the mind becomes less important and basically falls out of use. In the NHK Special I mention is a woman who gets righteously angry whenever social workers come by to get her to take her medicine or try and talk her into moving into a group home. She values her independence and rails against their meddling purposes, but it’s easy to conclude that these occasional interactions are the only stimulation she has, that her anger is a kind of compensating function for all the time she spends in her dark, cluttered room in the heart of Tokyo doing nothing except mooning nostalgically over a past that probably didn’t exist in the way she imagines it did. As one person in the program says offhandedly, by the time a person turns 95, chances are he or she will be senile. This is meant to sound shocking but when you think about it it isn’t. 95? Fifty years ago it would have been considered a miracle to reach that age. Now that it’s more easily achievable, the fact that people tend to lose part of their minds when they do achieve it shouldn’t be surprising. It’s like cancer. The older you are, the more likely it is that you’ll contract cancer. It has nothing to do with lifestyle and everything to do with normal biology, and if you had to think about it all the time as you grow old, you’ll lose your mind, too.