Lisa Dusseault raises a couple of interesting questions about the nature of fear in modern society. Why, she (implicitly) asks, do people's specific fears often correlate so poorly with the real dangers they actually face? And why are overall levels of human anxiety still so high in our society, given that our lives are spectacularly safer, by every rational measure, than ever before in history?

Well, I'm no behavioral biologist, but I figure I can construct "just so stories" with the best of them. So here goes....

Fear is a biological reaction, like pleasure or rage, and is designed to perform certain basic survival functions, like triggering avoidance of certain perennial dangers (snakes, heights) and assisting us in learning to avoid newly encountered threats (hot stoves, musclebound bullies). Like other limbic-system mechanisms that tie into higher congitive layers, though, it is prone to the creation of accidental superfluous associations. (A single adverse reaction to eating a particular food can cause a lifelong aversion to the taste of that food, even if it's normally safe and nutritious. And I'll just mention, without elaboration, the word, "fetish".) From an evolutionary point of view, this is perfectly reasonable; after all, it's far better for an individual to develop an unnecessary fear of, say, rabbits than to fail to develop a fear of tigers.

The lack of a correlation between overall fear level and overall safety level is perhaps more interesting, because it's even more strongly counterintuitive. Our anxiety levels do seem roughly to track our relative perceived danger levels; that is, we tend to get more fearful when we sense great danger. Shouldn't there also be, then, some correlation with absolute danger levels, which have in fact declined markedly over the centuries?

I can imagine a number of possible answers:

We really are less anxious than our ancestors. How do we know how much anxiety people felt during the Middle Ages, anyway? Or even people in dire circumstances elsewhere in the world today? Sure, footage of people living in squalor in third-world hellholes shows them seeming remarkably at peace with themselves and the world compared to Western city-dwellers, but perhaps that's just an illusion or cultural misunderstanding. For example, it may just be that....

The wages of fear have declined. One characteristic of modern, affluent, free societies is that betraying one's anxiety levels carries essentially no price. In other times and places, showing fear may well have meant quick death in many common circumstances, and fear would therefore have been suppressed much more often than it is in today's Western culture. It may therefore be that we actually do experience much less fear than people used to--but we talk about minor fears the way no one would have discussed even deathly terrors in the past. Or perhaps the reverse is true: we work ourselves into frenzies of panic today where our ancestors would have "managed" their fears more effectively by stifling their expression.

There's more to life than survival. That which may reduce mating potential, for instance, or safety of relatives, or their mating potential, ought to be viewed with as much alarm as that which may reduce lifespan. And threats to attractiveness (such as highly attractive competitors with large stores of resources to offer) certainly haven't declined along with physical dangers.

Fear of the inevitable is useless. A relatively likely threat about which nothing can be done is less worth fearing than a rare danger whose likelihood can be substantially reduced. Now, it sometimes seems as though the opposite is true: we tend to fear situations characterized by helplessness (such as airplane travel) much more than those where we maintain control (such as driving), even when the latter are considerably more dangerous. However, the fear in those cases exists to deter us from getting into situations of powerlessness in the first place--an act we often have a choice about. People who find themselves in dangerous situations they truly have no choice but to endure--those whose neighborhoods have become war zones or high-crime areas, for instance--often quickly become inured to their new risks, which they feel powerless to reduce. The same goes for people who live in circumstances where injury, disease, famine and violence are endemic and essentially unavoidable. However, the myriad options we enjoy in our lives also give us lots of opportunities to fear making dangerous choices that will send us hurtling ineluctably toward disaster.

To paraphrase the old joke, I don't have to outfear the bear, I just have to outfear you. In the pre-civilized world, dangers would always have been abundant enough to saturate our ability to fear them. There would thus have been an optimal "fear rate" (anxiety level) which would have provided the best possible tradeoff between the danger-avoiding benefits and the distraction from productive tasks provided by fears. This level would have been selected for through competition between human populations for survival, resulting in our current range of anxiety levels. (Variation in anxiety levels would also be advantageous; a community consisting of fearless warriors and panicky lookouts would do better than a uniform population of either.) Today, our anxiety levels, like our appetites for sugar, are relics of the age of never-ending threats, and we simply distribute them among more and more trivial worries.

Ignorance is bliss. In other times, people had very little access to information about dangers, and thus were happy to rely, of necessity, on authorities to tell them comforting (if largely fanciful) stories about how to protect themselves. Today, on the other hand, we have a world of highly decentralized information, in which even the government cannot really be trusted to give reliable information--to say nothing of that ignoramus posting reckless, completely uninformed speculations about the evolution of human nature to his blog. What a frightening state of affairs!