Fear is an adaptive emotion, phylogenetically ancient, and anatomically located mostly in the amygdala, which is part of the limbic system. Understanding fear, however, is about more than neuroanatomy. It is interesting to think what people generally fear, why, and what do they do about it.

Fear is an anxious feeling that can focus on either a current active threat (like being chased by a predator) or on the anticipation of a future negative event. It’s easy to see how that feeling would be adaptive – we worry about bad things happening in the future so that we will take action to prevent or at least mitigate them.

What We Fear?

Psychologists have identified five basic fears, out of which most other fears are based. They are: fear of death, mutilation, loss of autonomy, separation, and “ego death” which is the fear of humiliation or shame.

Despite the obvious adaptive function of fear, many people fear the wrong things, meaning that their fear and anxiety is not proportional to actual threat. This mismatch is maladaptive, so why is it the case?

For example, people generally fear flying more than driving. Meanwhile, in the entire history of aviation about 13,000 people have lost their lives, the same amount as die on US roads every 4 months. Another way to look at the probability, which is perhaps a bit more intuitive, is that you would have to fly every day for about 14,000 years before having a greater than 50% chance of crashing. That’s pretty reassuring.

Why do so many people worry about the (statistically) wrong things? There are a couple of reasons.

The first is that humans are intuitively terrible at probability. For most of us, our brains are just not built to be comfortable with large numbers. That is why people gamble and play the lottery.

Another reason is the availability heuristic. A heuristic is a mental short-cut that most people tend to make, without thinking. It is true enough most of the time to be an efficient assumption, but it is not strictly logically true. The availability heuristic is the tendency to assume that something is common or likely if we are easily able to think of an example.

This may have been adaptive when we lived in small communities. If you knew of people who were killed by large predators while hunting north of the river, you might assume it’s a good idea to avoid going north of the river. We probably didn’t evolve from those who ventured north of the river anyway.

However, now we live in a large society with a mass media. This means that the probability of us hearing a story about something happening is completely distorted. The media can draw interesting stories (in the US, for example) from 300 million people, and then we hear about them. We don’t hear about them because they are common or likely or happened in our neighborhood, we hear about them because the media is selecting them from a massive number of people.

Our availability heuristic kicks in, however, and we are given the false sense that the events we see on the news are common or likely. Therefore, the news has a tendency to give us a distorted view of reality. They also tend to focus on fears, because that is what sells. “Should you be afraid of X? Find out at 11.”

Therefore, people are afraid of shark attacks, being killed by terrorists, child abduction, and road rage even though those are all extremely rare events.

Social media has made the problem worse, if anything. There is an entire cottage industry that exists to sell fears about food and toxins. People worry about trace amounts of “chemicals” in their food rather than whether or not they are getting enough exercise.

What Should You Fear?

Optimally our fears would be proportional to the actual risk they pose. Actually I think there are three basic factors that should be taken explicitly into account when considering the appropriate level of fear and what to do about it. The first is the probability of the negative even occurring. The second is the consequences of the negative event. The third is the cost (expense, inconvenience, trade-offs) of taking steps to prevent or mitigate the negative event.

Physicians take a similar approach to disease – how likely is it, how bad is it, how treatable is it, and what are the total costs (including risks and side effects) of diagnosing and treating it?

So – if a negative outcome is likely, devastating, and cheap and easy to prevent, that is a no-brainer. I just described vaccines, for example. They are cheap and easy, with very low risk, and they are effective at preventing diseases that are likely and range from annoying to deadly if they occur.

Plane crashes are very unlikely, although devastating if they occur, and there is nothing you can do about it anyway, so don’t worry. You could avoid flying, but then you have to consider the consequences of that action. If you drive instead of fly, your net risk might increase. If you avoid travel, that might limit your opportunities and quality of life.

As a society we also have to decide on what to fear, and what steps we should take. Here are some interesting examples:

Asteroid strike – Getting hit by a large asteroid is very unlikely over the short term, but a near certainty over millions of years. The consequences could be total – human extinction. The only real downside to doing something to identify and redirect asteroids headed our way is the expense. However, given the risks it seems that the world could afford a few billion dollars to defend ourselves.

Coronal Mass Ejection – This, in my opinion, is one of the great underrated fears. CME’s are not uncommon, and a large one directed at Earth should happen every couple centuries or so. This is also not a matter of if but when. When we do get struck by a large CME, it could wipe out our satellite infrastructure and maybe even take out our electrical grid. Imagine months, or possibly years, without electricity. It would cost billions to harden our infrastructure against a CME, and to have backup equipment to rapidly replace critical items that are destroyed (like large transformers), but if we don’t do this a large CME can cost us trillions on the back end.

Antibiotic resistance – This too is an underrated fear. Bacteria are quickly evolving resistance to our antibiotics. In the worst case we might enter a post-antibiotic era. The steps to prevent , delay, or minimize this are all win-win – practicing good medicine, and researching new antibiotics. There is no down-side. The problem is that many of the measures are diffuse, meaning we need to get everyone to adopt best practices, and it’s difficult to get everyone to do anything. This one is a bit hard to predict, because technological advances could put off a crisis indefinitely. But such advances are difficult to predict with any precision.

Global warming – AGW is obviously a politically hot topic. Interestingly, the exact factors I name above are part of the debate – how likely is it that AGW is happening, what are the consequences, and what are the costs of steps to prevent or mitigate it? The scientific consensus is that it is likely, and the consequences are likely to be bad. The real debate, in my opinion, should focus on the third question – what measures are available, what are their costs, and how well will they work? We need to consider all options, but I think the best options are the win-wins – technological advances that create clean energy or increase energy efficiency are a win for everyone.

Conclusion

Fear and anxiety are adaptive emotions, but their net effect in a complex technological civilization is not always adaptive. Not surprisingly for a skeptic, I find that backing up our intuitions with an analytical approach is extremely helpful.

Fear can be a net negative when it is hugely distorted, and fear can be manipulated by people with an agenda. Analyzing actual probability, and going through a thoughtful analysis will help put our fears into perspective and identify measures that are likely to be helpful rather than harmful.