10/06/2014 01:49 pm ET

Ebola: A Warning That We Need to Vaccinate Ourselves...From Excessive Fear.

The common definition of risk is 'the probability of an adverse outcome or event' other words, the chance of something bad happening; losing your life, your health, your home, your money. The problem is, when most of us wonder "what's the risk of...?" we focus too much on the probability part...the odds...the statistical chance of that bad thing happening. And the problem there is that while the odds may be calculable, "bad' is entirely subjective, a matter of how the outcome feels, not how likely it is.

As Paul Slovic, a pioneer in the research of the psychology of risk perception, has put it, "risk is a feeling". And the fear of Ebola is a perfect example. The news is full of dramatic stories about the outbreak in western Africa of this scary disease, the deadliest Ebola outbreak in history, and now there is a case here, and Americans trying to contain the outbreak overseas have become victims and traveled home for treatment.

Small wonder, the fear. In the WHO information page about Ebola here's how they describe the symptoms;

...a severe acute viral illness often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.

You know, like bleeding out of your eyeballs and nose and mouth... while all that other awful suffering is also going on and you lose bodily fluids and your skin boils up in horrific pustules... and then you almost certainly die!

Ebola is untreatable, and if you get infected, chances are high that you will die. Fatality rates in this outbreak are in the 60 percent range, but different strains kill as many as 90 percent of those infected.

Terrible suffering. No control. No hope. And now (in the U.S.) it's HERE, where YOU live. How does that feel? Undoubtedly pretty scary. Might it relieve your fears at all to know that the odds that you will get this disease are infinitesimal? Not only would

1. someone who is infected have to get on a plane and get through customs both at departure and at the destination (less likely since folks traveling from those destinations -- Guinea, Sierra Leone, and Liberia -- are now getting extra scrutiny, but as Mr. Duncan in Dallas has shown, it is possible.)

2. but for them to infect you, and this is the big one, you would have to come into direct contact with their infectious bodily fluids... and get those fluids on an opening in your skin. Ebola does not transmit in the air, the way we assume many viruses do.

The chances of that are so tiny that... well, it would be ridiculous for anyone not in that region, or even in Dallas, to worry about it.

But worry about Ebola we do. And those worries have nothing to do with the odds of dying. The thing that matters is what if would feel like to BECOME dead. It's the process that's scary, more than the outcome itself. When Slovic and colleagues asked people to rank the risks they worried about most, the ones that rated highest shared these characteristics... great pain and suffering, a lack of control, and a sense that "It could happen to ME!". Those conditions make any risk scarier, regardless of the odds.

The problem is... our emotional relationship to risk can be a huge threat all by itself. Fear of flying -- we can't control it and dying that way would be horrific -- leads to driving, which feels like taking control, but which is far more likely to cause 'an adverse occurrence or event.'

Even just worrying too much, for too long, can be a risk, a BIG one. Worrying, biologically, is stress, and chronic stress (lasting more than several days) raises our blood pressure and heart rate, weakens our immune system, and interferes with normal neurotransmitter production. Chronic stress is associated with greater risk of heart disease, a higher likelihood of catching infectious disease (or suffering more from them if we do), clinical depression, infertility, and other serious health problems.

We can't undo these feelings. But what we can do is use this outbreak to help realize how our fear is sometimes disproportionate to the probability of the risk, and recognize that in order to diagnose another health risk we all face... The Risk Perception Gap... when because of the emotional and instinctive way we perceive risk we fear too much, or too little, and do things that are risky all by themselves.

We can try to vaccinate ourselves against that. And we should. Odds are we'd all be better off.